Polymers for use in electronic devices

ABSTRACT

Disclosed is a polyimide having a repeat unit structure of Formula IV 
     
       
         
         
             
             
         
       
     
     In Formula IV: R a  is the same or different at each occurrence and represents one or more tetracarboxylic acid component residues; and R b  is the same or different at each occurrence and represents one or more aromatic diamine residues. 30-100 mol % of R b  has Formula II 
     
       
         
         
             
             
         
       
     
     In Formula II: R 1  and R 2  are the same or different at each occurrence and are halogen, alkyl, fluoroalkyl, silyl, alkoxy, fluoroalkoxy, or siloxy; a and b are the same or different and are an integer from 0-4; c and d are the same or different and are 1 or 2; and * indicates a point of attachment.

CLAIM OF BENEFIT OF PRIOR APPLICATION

This application claims the benefit of U.S. Provisional Application No.62/715,422, filed Aug. 7, 2018, which is incorporated in its entiretyherein by reference.

BACKGROUND INFORMATION Field of the Disclosure

The present disclosure relates to novel polymeric compounds. Thedisclosure further relates to methods for preparing such polymericcompounds and electronic devices having at least one layer comprisingthese materials.

Description of the Related Art

Materials for use in electronics applications often have strictrequirements in terms of their structural, optical, thermal, electronic,and other properties. As the number of commercial electronicsapplications continues to increase, the breadth and specificity ofrequisite properties demand the innovation of materials with new and/orimproved properties. Polyimides represent a class of polymeric compoundsthat has been widely used in a variety of electronics applications. Theycan serve as a flexible replacement for glass in electronic displaydevices provided that they have suitable properties. These materials canfunction as a component of Liquid Crystal Displays (“LCDs”), where theirmodest consumption of electrical power, light weight, and layer flatnessare critical properties for effective utility. Other uses in electronicdisplay devices that place such parameters at a premium include devicesubstrates, substrates for color filter sheets, cover films, touchscreen panels, and others.

A number of these components are also important in the construction andoperation of organic electronic devices having an organic light emittingdiode (“OLED”). OLEDs are promising for many display applicationsbecause of their high power conversion efficiency and applicability to awide range of end-uses. They are increasingly being used in cell phones,tablet devices, handheld/laptop computers, and other commercialproducts. These applications call for displays with high informationcontent, full color, and fast video rate response time in addition tolow power consumption.

Polyimide films generally possess sufficient thermal stability, highglass transition temperature, and mechanical toughness to meritconsideration for such uses. Also, polyimides generally do not develophaze when subject to repeated flexing, so they are often preferred overother transparent substrates like polyethylene terephthalate (PET) andpolyethylene naphthalate (PEN) in flexible display applications.

The traditional amber color of polyimides, however, precludes their usein some display applications such as color filters and touch screenpanels since a premium is placed on optical transparency. Further,polyimides are generally stiff, highly aromatic materials; and thepolymer chains tend to orient in the plane of the film/coating as thefilm/coating is being formed. This leads to differences in refractiveindex in the parallel vs. perpendicular directions of the film(birefringence) which produces optical retardation that can negativelyimpact display performance. If polyimides are to find additionalapplications in the displays market, a solution is needed to maintaintheir desirable properties, while at the same time improving theiroptical transparency and reducing the amber color and birefringence thatleads to optical retardation.

There is thus a continuing need for polymer materials that are suitablefor use in electronic devices.

SUMMARY

There is provided a polyamic acid having Formula I

where:

-   -   R^(a) is the same or different at each occurrence and represents        one or more tetracarboxylic acid component residues; and    -   R^(b) is the same or different at each occurrence and represents        one or more aromatic diamine residues;        wherein 30-100 mol % of R^(b) has Formula II

where:

-   -   R¹ and R² are the same or different at each occurrence and are        selected from the group consisting of halogen, alkyl,        fluoroalkyl, silyl, alkoxy, fluoroalkoxy, and siloxy;    -   a and b are the same or different and are an integer from 0-4;    -   c and d are the same or different and are 1 or 2; and    -   * indicates a point of attachment.

There is further provided a composition comprising (a) the polyamic acidhaving Formula I and (b) a high-boiling, aprotic solvent.

There is further provided a polyimide whose repeat units have thestructure in Formula IV

where R^(a) and R^(b) are as defined in Formula I.

There is further provided a polyimide film comprising the repeat unit ofFormula IV.

There is further provided one or more methods for preparing a polyimidefilm wherein the polyimide film has the repeat unit of Formula IV.

There is further provided a flexible replacement for glass in anelectronic device wherein the flexible replacement for glass is apolyimide film having the repeat unit of Formula IV.

There is further provided an electronic device having at least one layercomprising a polyimide film having the repeat unit of Formula IV.

There is further provided an organic electronic device, such as an OLED,wherein the organic electronic device contains a flexible replacementfor glass as disclosed herein.

The foregoing general description and the following detailed descriptionare exemplary and explanatory only and are not restrictive of theinvention, as defined in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated in the accompanying figures to improveunderstanding of concepts as presented herein.

FIG. 1 includes an illustration of one example of a polyimide film thatcan act as a flexible replacement for glass.

FIG. 2 includes an illustration of one example of an electronic devicethat includes a flexible replacement for glass.

Skilled artisans appreciate that objects in the figures are illustratedfor simplicity and clarity and have not necessarily been drawn to scale.For example, the dimensions of some of the objects in the figures may beexaggerated relative to other objects to help to improve understandingof embodiments.

DETAILED DESCRIPTION

There is provided a polyamic acid having Formula I, as described indetail below.

There is further provided a composition comprising (a) the polyamic acidhaving Formula I and (b) a high-boiling, aprotic solvent.

There is further provided a polyimide whose repeat units have thestructure in Formula IV, as described in detail below.

There is further provided one or more methods for preparing a polyimidefilm wherein the polyimide film has the repeat unit of Formula IV.

There is further provided a flexible replacement for glass in anelectronic device wherein the flexible replacement for glass is apolyimide film having the repeat unit of Formula IV.

There is further provided an electronic device having at least one layercomprising a polyimide film having the repeat unit of Formula IV.

There is further provided an organic electronic device, such as an OLED,wherein the organic electronic device contains a flexible replacementfor glass as disclosed herein.

Many aspects and embodiments have been described above and are merelyexemplary and not limiting. After reading this specification, skilledartisans appreciate that other aspects and embodiments are possiblewithout departing from the scope of the invention.

Other features and benefits of any one or more of the embodiments willbe apparent from the following detailed description, and from theclaims. The detailed description first addresses Definitions andClarification of Terms, followed by the Polyamic Acid Having the RepeatUnit Structure of Formula I, the Polyimide Having the Repeat UnitStructure of Formula IV, the Methods for Preparing the Polyimide Films,the Electronic Device, and finally Examples.

1. Definitions and Clarification of Terms

Before addressing details of embodiments described below, some terms aredefined or clarified.

As used in the “Definitions and Clarification of Terms”, R, R^(a),R^(b), R′, R″ and any other variables are generic designations and maybe the same as or different from those defined in the formulas.

The term “alignment layer” is intended to mean a layer of organicpolymer in a liquid-crystal device (LCD) that aligns the moleculesclosest to each plate as a result of its being rubbed onto the LCD glassin one preferential direction during the LCD manufacturing process.

As used herein, the term “alkyl” includes branched and straight-chainsaturated aliphatic hydrocarbon groups. Unless otherwise indicated, theterm is also intended to include cyclic groups. Examples of alkyl groupsinclude methyl, ethyl, propyl, isopropyl, isobutyl, secbutyl, tertbutyl,pentyl, isopentyl, neopentyl, cyclopentyl, hexyl, cyclohexyl, isohexyland the like. The term “alkyl” further includes both substituted andunsubstituted hydrocarbon groups. In some embodiments, the alkyl groupmay be mono-, di- and tri-substituted. One example of a substitutedalkyl group is trifluoromethyl. Other substituted alkyl groups areformed from one or more of the substituents described herein. In certainembodiments alkyl groups have 1 to 20 carbon atoms. In otherembodiments, the group has 1 to 6 carbon atoms. The term is intended toinclude heteroalkyl groups. Heteroalkyl groups may have from 1-20 carbonatoms.

The term “aprotic” refers to a class of solvents that lack an acidichydrogen atom and are therefore incapable of acting as hydrogen donors.Common aprotic solvents include alkanes, carbon tetrachloride (CCl4),benzene, dimethyl formamide (DMF), N-methyl-2-Pyrrolidone (NMP),dimethylacetamide (DMAc), and many others.

The term “aromatic compound” is intended to mean an organic compoundcomprising at least one unsaturated cyclic group having 4n+2 delocalizedpi electrons. The term is intended to encompass both aromatic compoundshaving only carbon and hydrogen atoms, and heteroaromatic compoundswherein one or more of the carbon atoms within the cyclic group has beenreplaced by another atom, such as nitrogen, oxygen, sulfur, or the like.

The term “aryl” or “aryl group” a moiety formed by removal of one ormore hydrogen (“H”) or deuterium (“D”) from an aromatic compound. Thearyl group may be a single ring (monocyclic) or have multiple rings(bicyclic, or more) fused together or linked covalently. A “hydrocarbonaryl” has only carbon atoms in the aromatic ring(s). A “heteroaryl” hasone or more heteroatoms in at least one aromatic ring. In someembodiments, hydrocarbon aryl groups have 6 to 60 ring carbon atoms, insome embodiments, 6 to 30 ring carbon atoms. In some embodiments,heteroaryl groups have from 4-50 ring carbon atoms, in some embodiments,4-30 ring carbon atoms.

The term “alkoxy” is intended to mean the group —OR, where R is alkyl.

The term “aryloxy” is intended to mean the group —OR, where R is aryl.

Unless otherwise indicated, all groups can be substituted orunsubstituted. An optionally substituted group, such as, but not limitedto, alkyl or aryl, may be substituted with one or more substituentswhich may be the same or different. Suitable substituents include alkyl,aryl, nitro, cyano, —N(R′)(R″), halo, hydroxy, carboxy, alkenyl,alkynyl, cycloalkyl, heteroaryl, alkoxy, aryloxy, heteroaryloxy,alkoxycarbonyl, perfluoroalkyl, perfluoroalkoxy, arylalkyl, silyl,siloxy, siloxane, thioalkoxy, —S(O)₂—, —C(═O)—N(R′)(R″),(R′)(R″)N-alkyl, (R′)(R″)N-alkoxyalkyl, (R′)(R″)N-alkylaryloxyalkyl,—S(O)_(s)-aryl (where s=0-2) or —S(O)_(s)-heteroaryl (where s=0-2). EachR′ and R″ is independently an optionally substituted alkyl, cycloalkyl,or aryl group. R′ and R″, together with the nitrogen atom to which theyare bound, can form a ring system in certain embodiments. Substituentsmay also be crosslinking groups.

The term “amine” is intended to mean a compound that contains a basicnitrogen atom with a lone pair, where “lone pair” refers to a set of twovalence electrons that are not shared with another atom. The term“amino” refers to the functional group —NH₂, —NHR, or —NR₂, where R isthe same or different at each occurrence and can be an alkyl group or anaryl group. The term “diamine” is intended to mean a compound thatcontains two basic nitrogen atoms with associated lone pairs. The term“aromatic diamine” is intended to mean an aromatic compound having twoamino groups. The term “bent diamine” is intended to mean a diaminewherein the two basic nitrogen atoms and associated lone pairs areasymmetrically disposed about the center of symmetry of thecorresponding compound or functional group, e.g. m-phenylenediamine:

The term “aromatic diamine residue” is intended to mean the moietybonded to the two amino groups in an aromatic diamine. The term“aromatic diisocyanate residue” is intended to mean the moiety bonded tothe two isocyanate groups in an aromatic diisocyanate compound. This isfurther illustrated below.

Diamine/Diisocyanate Residue

The terms “diamine residue” and “diisocyanate residue” are intended tomean the moiety bonded to two amino groups or two isocyanate groups,respectively, where the moiety may be aliphatic or aromatic.

The term “b*” is intended to mean the b* axis in the CIELab Color Spacethat represents the yellow/blue opponent colors. Yellow is representedby positive b* values, and blue is represented by negative b* values.Measured b* values may be affected by solvent, particularly sincesolvent choice may affect color measured on materials exposed tohigh-temperature processing conditions. This may arise as the result ofinherent properties of the solvent and/or properties associated with lowlevels of impurities contained in various solvents. Particular solventsare often preselected to achieve desired b* values for a particularapplication.

The term “birefringence” is intended to mean the difference in therefractive index in different directions in a polymer film or coating.This term usually refers to the difference between the x- or y-axis(in-plane) and the z-axis (out-of-plane) refractive indices.

The term “charge transport,” when referring to a layer, material,member, or structure is intended to mean such layer, material, member,or structure facilitates migration of such charge through the thicknessof such layer, material, member, or structure with relative efficiencyand small loss of charge. Hole transport materials facilitate positivecharge, electron transport materials facilitate negative charge.Although light-emitting materials may also have some charge transportproperties, the term “charge transport layer, material, member, orstructure” is not intended to include a layer, material, member, orstructure whose primary function is light emission.

The term “compound” is intended to mean an electrically unchargedsubstance made up of molecules that further include atoms, wherein theatoms cannot be separated from their corresponding molecules by physicalmeans without breaking chemical bonds. The term is intended to includeoligomers and polymers.

The term “linear coefficient of thermal expansion (CTE or α)” isintended to mean the parameter that defines the amount which a materialexpands or contracts as a function of temperature. It is expressed asthe change in length per degree Celsius and is generally expressed inunits of μm/m/° C. or ppm/° C.

α=(ΔL/L ₀)/ΔT

Measured CTE values disclosed herein are made via known methods duringthe first or second heating scan. The understanding of the relativeexpansion/contraction characteristics of materials can be an importantconsideration in the fabrication and/or reliability of electronicdevices.

The term “dopant” is intended to mean a material, within a layerincluding a host material, that changes the electronic characteristic(s)or the targeted wavelength(s) of radiation emission, reception, orfiltering of the layer compared to the electronic characteristic(s) orthe wavelength(s) of radiation emission, reception, or filtering of thelayer in the absence of such material.

The term “electroactive” as it refers to a layer or a material, isintended to indicate a layer or material which electronicallyfacilitates the operation of the device. Examples of electroactivematerials include, but are not limited to, materials which conduct,inject, transport, or block a charge, where the charge can be either anelectron or a hole, or materials which emit radiation or exhibit achange in concentration of electron-hole pairs when receiving radiation.Examples of inactive materials include, but are not limited to,planarization materials, insulating materials, and environmental barriermaterials.

The term “tensile elongation” or “tensile strain” is intended to meanthe percentage increase in length that occurs in a material before itbreaks under an applied tensile stress. It can be measured, for example,by ASTM Method D882.

The prefix “fluoro” is intended to indicate that one or more hydrogensin a group have been replaced with fluorine.

The term “glass transition temperature (or T_(g))” is intended to meanthe temperature at which a reversible change occurs in an amorphouspolymer or in amorphous regions of a semi crystalline polymer where thematerial changes suddenly from a hard, glassy, or brittle state to onethat is flexible or elastomeric. Microscopically, the glass transitionoccurs when normally-coiled, motionless polymer chains become free torotate and can move past each other. T_(g)'s may be measured usingdifferential scanning calorimetry (DSC), thermo-mechanical analysis(TMA), or dynamic-mechanical analysis (DMA), or other methods.

The prefix “hetero” indicates that one or more carbon atoms have beenreplaced with a different atom. In some embodiments, the heteroatom isO, N, S, or combinations thereof.

The term “high-boiling” is intended to indicate a boiling point greaterthan 130° C.

The term “host material” is intended to mean a material to which adopant is added. The host material may or may not have electroniccharacteristic(s) or the ability to emit, receive, or filter radiation.In some embodiments, the host material is present in higherconcentration.

The term “isothermal weight loss” is intended to mean a material'sproperty that is directly related to its thermal stability. It isgenerally measured at a constant temperature of interest viathermogravimetric analysis (TGA). Materials that have high thermalstability generally exhibit very low percentages of isothermal weightloss at the required use or processing temperature for the desiredperiod of time and can therefore be used in applications at thesetemperatures without significant loss of strength, outgassing, and/orchange in structure.

The term “liquid composition” is intended to mean a liquid medium inwhich a material is dissolved to form a solution, a liquid medium inwhich a material is dispersed to form a dispersion, or a liquid mediumin which a material is suspended to form a suspension or an emulsion.

The term “matrix” is intended to mean a foundation on which one or morelayers is deposited in the formation of, for example, an electronicdevice. Non-limiting examples include glass, silicon, and others.

The term “1% TGA Weight Loss” is intended to mean the temperature atwhich 1% of the original polymer weight is lost due to decomposition(excluding absorbed water).

The term “optical retardation (or R_(TH))” is intended to mean thedifference between the average in-plane refractive index and theout-of-plane refractive index (i.e., the birefringence), this differencethen being multiplied by the thickness of the film or coating. Opticalretardation is typically measured for a given frequency of light, andthe units are reported in nanometers.

The term “organic electronic device” or sometimes “electronic device” isherein intended to mean a device including one or more organicsemiconductor layers or materials.

The term “particle content” is intended to mean the number or count ofinsoluble particles that is present in a solution. Measurements ofparticle content can be made on the solutions themselves or on finishedmaterials (pieces, films, etc.) prepared from those films. A variety ofoptical methods can be used to assess this property.

The term “photoactive” refers to a material or layer that emits lightwhen activated by an applied voltage (such as in a light emitting diodeor chemical cell), that emits light after the absorption of photons(such as in down-converting phosphor devices), or that responds toradiant energy and generates a signal with or without an applied biasvoltage (such as in a photodetector or a photovoltaic cell).

The term “polyamic acid solution” refers to a solution of a polymercontaining amic acid units that have the capability of intramolecularcyclization to form imide groups.

The term “polyimide” refers to condensation polymers resulting from thereaction of one or more polyfunctional carboxylic acid components withone or more primary polyamines or polyisocyanates. They contain theimide structure —CO—NR—CO— as a linear or heterocyclic unit along themain chain of the polymer backbone. In some embodiments, the polyimideresults from the reaction of one or more bifunctional carboxylic acidcomponents with one or more primary diamines or diisocyanates.

The term “satisfactory,” when regarding a materials property orcharacteristic, is intended to mean that the property or characteristicfulfills all requirements/demands for the material in-use. For example,an isothermal weight loss of less than 1% at 350° C. for 3 hours innitrogen can be viewed as a non-limiting example of a “satisfactory”property in the context of the polyimide films disclosed herein.

The term “soft-baking” is intended to mean a process commonly used inelectronics manufacture wherein coated materials are heated to drive offsolvents and solidify a film. Soft-baking is commonly performed on a hotplate or in exhausted oven at temperatures between 90° C. and 110° C. asa preparation step for subsequent thermal treatment of coated layers orfilms.

The term “substrate” refers to a base material that can be either rigidor flexible and may include one or more layers of one or more materials,which can include, but are not limited to, glass, polymer, metal orceramic materials or combinations thereof. The substrate may or may notinclude electronic components, circuits, or conductive members.

The term “siloxane” refers to the group R₃SiOR₂Si—, where R is the sameor different at each occurrence and is H, C1-20 alkyl, fluoroalkyl, oraryl. In some embodiments, one or more carbons in an R alkyl group arereplaced with Si.

The term “siloxy” refers to the group R₃SiO—, where R is the same ordifferent at each occurrence and is H, C1-20 alkyl, fluoroalkyl, oraryl.

The term “silyl” refers to the group R₃Si—, where R is the same ordifferent at each occurrence and is H, C1-20 alkyl, fluoroalkyl, oraryl. In some embodiments, one or more carbons in an R alkyl group arereplaced with Si.

The term “spin coating” is intended to mean a process used to deposituniform thin films onto flat substrates. Generally, a small amount ofcoating material is applied on the center of the substrate, which iseither spinning at low speed or not spinning at all. The substrate isthen rotated at specified speeds in order to spread the coating materialuniformly by centrifugal force.

The term “laser particle counter test” refers to a method used to assessthe particle content of polyamic acid and other polymeric solutionswhereby a representative sample of a test solution is spin coated onto a5″ silicon wafer and soft baked/dried. The film thus prepared isevaluated for particle content by any number of standard measurementtechniques. Such techniques include laser particle detection and othersknown in the art.

The term “tensile modulus” is intended to mean the measure of thestiffness of a solid material that defines the initial relationshipbetween the stress (force per unit area) and the strain (proportionaldeformation) in a material like a film. Commonly used units are gigapascals (GPa).

The term “tetracarboxylic acid component” is intended to mean any one ormore of the following: a tetracarboxylic acid, a tetracarboxylic acidmonoanhydride, a tetracarboxylic acid dianhydride, a tetracarboxylicacid monoester, and a tetracarboxylic acid diester.

The term “tetracarboxylic acid component residue” is intended to meanthe moiety bonded to the four carboxy groups in a tetracarboxylic acidcomponent. This is further illustrated below.

Tetracarboxylic acid component Residue

The term “transmittance” refers to the percentage of light of a givenwavelength impinging on a film that passes through the film so as to bedetectable on the other side. Light transmittance measurements in thevisible region (380 nm to 800 nm) are particularly useful forcharacterizing film-color characteristics that are most important forunderstanding the properties-in-use of the polyimide films disclosedherein.

The term “yellowness index (or YI)” refers to the magnitude ofyellowness relative to a standard. A positive value of YI indicates thepresence, and magnitude, of a yellow color. Materials with a negative YIappear bluish. It should also be noted, particularly for polymerizationand/or curing processes run at high temperatures, that YI can be solventdependent. The magnitude of color introduced using DMAC as a solvent,for example, may be different than that introduced using NMP as asolvent. This may arise as the result of inherent properties of thesolvent and/or properties associated with low levels of impuritiescontained in various solvents. Particular solvents are often preselectedto achieve desired YI values for a particular application.

In a structure where a substituent bond passes through one or more ringsas shown below,

it is meant that the substituent R may be bonded at any availableposition on the one or more rings.

The phrase “adjacent to,” when used to refer to layers in a device, doesnot necessarily mean that one layer is immediately next to anotherlayer. On the other hand, the phrase “adjacent R groups,” is used torefer to R groups that are next to each other in a chemical formula(i.e., R groups that are on atoms joined by a bond). Exemplary adjacentR groups are shown below:

In this specification, unless explicitly stated otherwise or indicatedto the contrary by the context of usage, where an embodiment of thesubject matter hereof is stated or described as comprising, including,containing, having, being composed of or being constituted by or ofcertain features or elements, one or more features or elements inaddition to those explicitly stated or described may be present in theembodiment. An alternative embodiment of the disclosed subject matterhereof, is described as consisting essentially of certain features orelements, in which embodiment features or elements that would materiallyalter the principle of operation or the distinguishing characteristicsof the embodiment are not present therein. A further alternativeembodiment of the described subject matter hereof is described asconsisting of certain features or elements, in which embodiment, or ininsubstantial variations thereof, only the features or elementsspecifically stated or described are present.

Further, unless expressly stated to the contrary, “or” refers to aninclusive or and not to an exclusive or. For example, a condition A or Bis satisfied by any one of the following: A is true (or present) and Bis false (or not present), A is false (or not present) and B is true (orpresent), and both A and B are true (or present).

Also, use of “a” or “an” are employed to describe elements andcomponents described herein. This is done merely for convenience and togive a general sense of the scope of the invention. This descriptionshould be read to include one or at least one and the singular alsoincludes the plural unless it is obvious that it is meant otherwise.

Group numbers corresponding to columns within the Periodic Table of theelements use the “New Notation” convention as seen in the CRC Handbookof Chemistry and Physics, 81^(st) Edition (2000-2001).

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of embodiments of the present invention, suitablemethods and materials are described below. All publications, patentapplications, patents, and other references mentioned herein areincorporated by reference in their entirety, unless a particular passageis cited. In case of conflict, the present specification, includingdefinitions, will control. In addition, the materials, methods, andexamples are illustrative only and not intended to be limiting.

To the extent not described herein, many details regarding specificmaterials, processing acts, and circuits are conventional and may befound in textbooks and other sources within the organic light-emittingdiode display, photodetector, photovoltaic, and semiconductive memberarts.

2. Polyamic Acid Having the Repeat Unit Structure of Formula I

The polyamic acid described herein has a repeat unit structure ofFormula I

where:

-   -   R^(a) is the same or different at each occurrence and represents        one or more tetracarboxylic acid component residues; and    -   R^(b) is the same or different at each occurrence and represents        one or more aromatic diamine residues;        wherein 30-100 mol % of R^(b) has Formula II

where:

-   -   R¹ and R² are the same or different at each occurrence and are        selected from the group consisting of halogen, alkyl,        fluoroalkyl, silyl, alkoxy, fluoroalkoxy, and siloxy;    -   a and b are the same or different and are an integer from 0-4;    -   c and d are the same or different and are 1 or 2; and    -   * indicates a point of attachment.

In some embodiments of Formula I, R^(a) represents a singletetracarboxylic acid component residue.

In some embodiments of Formula I, R^(a) represents two differenttetracarboxylic acid component residues.

In some embodiments of Formula I, R^(a) represents three differenttetracarboxylic acid residues.

In some embodiments of Formula I, R^(a) represents four differenttetracarboxylic acid residues.

In some embodiments of Formula I, R^(a) represents one or moretetracarboxylic acid dianhydride residues.

Examples of suitable aromatic tetracarboxylic acid dianhydrides include,but are not limited to, pyromellitic dianhydride (PMDA),3,3′,4,4′-biphenyl tetracarboxylic dianhydride (BPDA),4,4′-oxydiphthalic anhydride (ODPA),4,4′-hexafluoroiso-propylidenebisphthalic dianhydride (6FDA),3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA),3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride (DSDA),4,4′-bisphenol-A dianhydride (BPADA), hydroquinone diphthalic anhydride(HQDEA), ethylene glycol bis (trimellitic anhydride) (TMEG-100),4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronapthalene-1,2-dicarboxylicanhydride (DTDA); 4,4′-bisphenol A dianhydride (BPADA), and the like andcombinations thereof. These aromatic dianhydrides may optionally besubstituted with groups that are known in the art including alkyl, aryl,nitro, cyano, —N(R′)(R″), halo, hydroxy, carboxy, alkenyl, alkynyl,cycloalkyl, heteroaryl, alkoxy, aryloxy, heteroaryloxy, alkoxycarbonyl,perfluoroalkyl, perfluoroalkoxy, arylalkyl, silyl, siloxy, siloxane,thioalkoxy, —S(O)₂—, —C(═O)—N(R′)(R″), (R′)(R″)N-alkyl,(R′)(R″)N-alkoxyalkyl, (R′)(R″)N-alkylaryloxyalkyl, —S(O)_(s)-aryl(where s=0-2) or —S(O)_(s)-heteroaryl (where s=0-2). Each R′ and R″ isindependently an optionally substituted alkyl, cycloalkyl, or arylgroup. R′ and R″, together with the nitrogen atom to which they arebound, can form a ring system in certain embodiments. Substituents mayalso be crosslinking groups.

In some embodiments of Formula I, R^(a) represents one or more residuesfrom tetracarboxylic acid dianhydrides selected from the groupconsisting of PMDA, BPDA, 6FDA, and BTDA.

In some embodiments of Formula I, R^(a) represents a PMDA residue.

In some embodiments of Formula I, R^(a) represents a BPDA residue.

In some embodiments of Formula I, R^(a) represents a 6FDA residue.

In some embodiments of Formula I, R^(a) represents a BTDA residue.

In some embodiments of Formula I, R^(a) represents a PMDA residue and aBPDA residue.

In some embodiments of Formula I, R^(a) represents a PMDA residue and a6FDA residue.

In some embodiments of Formula I, R^(a) represents a PMDA residue and aBTDA residue.

In some embodiments of Formula I, R^(a) represents a BPDA residue and a6FDA residue.

In some embodiments of Formula I, R^(a) represents a BPDA residue and aBTDA residue.

In some embodiments of Formula I, R^(a) represents a 6FDA residue and aBTDA residue.

In Formula I, 30-100 mol % of R^(b) represents a diamine residue havingFormula II, as shown above. In some embodiments of Formula I, 40-100 mol% of R^(b) has Formula II; in some embodiments, 50-100 mol %; in someembodiments, 60-100 mol %; in some embodiments, 70-100 mol %; in someembodiments, 80-100 mol %; in some embodiments, 90-100 mol %; in someembodiments, 100%.

In some embodiments of Formula II, a=0.

In some embodiments of Formula II, a=1.

In some embodiments of Formula II, a=2.

In some embodiments of Formula II, a=3.

In some embodiments of Formula II, a=4.

In some embodiments of Formula II, a>0.

In some embodiments of Formula II, b=0.

In some embodiments of Formula II, b=1.

In some embodiments of Formula II, b=2.

In some embodiments of Formula II, b=3.

In some embodiments of Formula II, b=4.

In some embodiments of Formula II, b>0.

In some embodiments of Formula II, a=b.

In some embodiments of Formula II, a=b=0.

In some embodiments of Formula II, a=b=1.

In some embodiments of Formula II, c=1.

In some embodiments of Formula II, c=2.

In some embodiments of Formula II, d=1.

In some embodiments of Formula II, d=2.

In some embodiments of Formula II, c=d.

In some embodiments of Formula II, c=d=1.

In some embodiments of Formula II, a>0 and at least one R¹ is F.

In some embodiments of Formula II, a>0 and at least one R¹ is a C₁₋₈alkyl; in some embodiments, a C₁₋₃ alkyl.

In some embodiments of Formula II, a>0 and at least one R¹ is a C₁₋₈fluoroalkyl alkyl; in some embodiments, a C₁₋₃ fluoroalkyl.

In some embodiments of Formula II, a>0 and at least one R¹ is a C₁₋₈perfluoroalkyl alkyl; in some embodiments a C₁₋₃ perfluoroalkyl alkyl.

In some embodiments of Formula II, a>0 and at least one R¹ is a C₁₋₈alkoxy.

In some embodiments of Formula II, a>0 and at least one R¹ is a C₃₋₁₈silyl.

In some embodiments of Formula II, a>0 and at least one R¹ is a C₃₋₁₈siloxy.

In some embodiments of Formula II, a>0 and at least one R¹ is selectedfrom the group consisting of F and fluoroalkyl.

In some embodiments of Formula II, a>0 and at least one R¹ is selectedfrom the group consisting of F and perfluoroalkyl.

In some embodiments of Formula II, a>0 and at least one R¹ is selectedfrom the group consisting of F, methyl, and trifluoromethyl.

In some embodiments of Formula II, a>0, b>0, and R¹=R².

When b>0, all of the above-described embodiments for R¹ apply equally toR².

In some embodiments of Formula II, the diamine residue has Formula IIA

where R¹, R², a, b, c, d, and * are as defined above for Formula II.

All of the above-described embodiments for R¹, R², a, b, c, and d inFormula II, apply equally to R¹, R², a, b, c, and d in Formula IIA.

In some embodiments of Formula II, the diamine residue has Formula IIA-1

where:

-   -   R³ and R⁴ are the same or different and are selected from the        group consisting of H, halogen, alkyl, fluoroalkyl, silyl,        alkoxy, fluoroalkoxy, and siloxy; and    -   * indicates a point of attachment.

In some embodiments of Formula IIA-1, R³=H.

In some embodiments of Formula IIA-1, R⁴=H.

In some embodiments of Formula IIA-1, R³=R⁴.

In some embodiments of Formula IIA-1, R³=R⁴=H.

All of the above-described embodiments for R¹ in Formula II, applyequally to R³ and R⁴ in Formula IIA-1.

In some embodiments of Formula IIA-1, R³ is selected from the groupconsisting of F, C₁₋₅ fluoroalkyl, and C₁₋₅ fluoroalkoxy.

In some embodiments of Formula IIA-1, R⁴ is selected from the groupconsisting of F, C₁₋₅ fluoroalkyl, and C₁₋₅ fluoroalkoxy.

In some embodiments of Formula II, the diamine residue has Formula IIB

where R¹, R², a, b, c, d, and * are as defined above for Formula II.

All of the above-described embodiments for R¹, R², a, b, c, and d inFormula II, apply equally to R¹, R², a, b, c, and d in Formula IIB.

In some embodiments of Formula II, the diamine residue has Formula IIB-1

where:

-   -   R³ and R⁴ are the same or different and are selected from the        group consisting of H, halogen, alkyl, fluoroalkyl, silyl,        alkoxy, fluoroalkoxy, and siloxy; and    -   * indicates a point of attachment.

All of the above-described embodiments for R³ and R⁴ in Formula IIA-1,apply equally to R³ and R⁴ in Formula IIB-1.

In some embodiments of Formula II, the diamine residue has Formula IIC

where R¹, R², a, b, c, d, and * are as defined above for Formula II.

All of the above-described embodiments for R¹, R², a, b, c, and d inFormula II, apply equally to R¹, R², a, b, c, and d in Formula IIC.

In some embodiments of Formula II, the diamine residue has Formula IIC-1

where:

-   -   R³ and R⁴ are the same or different and are selected from the        group consisting of H, halogen, alkyl, fluoroalkyl, silyl,        alkoxy, fluoroalkoxy, and siloxy; and    -   * indicates a point of attachment.

All of the above-described embodiments for R³ and R⁴ in Formula IIA-1,apply equally to R³ and R⁴ in Formula IIC-1.

In some embodiments of Formula II, the diamine residue has Formula IID

where R¹, R², a, b, c, d, and * are as defined above for Formula II.

All of the above-described embodiments for R¹, R², a, b, c, and d inFormula II, apply equally to R¹, R², a, b, c, and d in Formula IID.

In some embodiments of Formula II, the diamine residue has Formula IID-1

where:

-   -   R³ and R⁴ are the same or different and are selected from the        group consisting of H, halogen, alkyl, fluoroalkyl, silyl,        alkoxy, fluoroalkoxy, and siloxy; and    -   * indicates a point of attachment.

All of the above-described embodiments for R³ and R⁴ in Formula IIA-1,apply equally to R³ and R⁴ in Formula IID-1.

In some embodiments of Formula II, the diamine residue has Formula IIE

where R¹, R², a, b, c, d, and * are as defined above for Formula II.

All of the above-described embodiments for R¹, R², a, b, c, and d inFormula II, apply equally to R¹, R², a, b, c, and d in Formula IIE.

In some embodiments of Formula II, the diamine residue has Formula IIE-1

where:

-   -   R³ and R⁴ are the same or different and are selected from the        group consisting of H, halogen, alkyl, fluoroalkyl, silyl,        alkoxy, fluoroalkoxy, and siloxy; and    -   * indicates a point of attachment.

All of the above-described embodiments for R³ and R⁴ in Formula IIA-1,apply equally to R³ and R⁴ in Formula IIE-1.

In some embodiments of Formula II, the diamine residue has Formula IIF

where R¹, R², a, b, c, d, and * are as defined above for Formula II.

All of the above-described embodiments for R¹, R², a, b, c, and d inFormula II, apply equally to R¹, R², a, b, c, and d in Formula IIF.

In some embodiments of Formula II, the diamine residue has Formula IIF-1

where:

-   -   R³ and R⁴ are the same or different and are selected from the        group consisting of H, halogen, alkyl, fluoroalkyl, silyl,        alkoxy, fluoroalkoxy, and siloxy; and    -   * indicates a point of attachment.

All of the above-described embodiments for R³ and R⁴ in Formula IIA-1,apply equally to R³ and R⁴ in Formula IIF-1.

Any of the above embodiments for Formula II can be combined with one ormore of the other embodiments, so long as they are not mutuallyexclusive. For example, the embodiment in which R¹ is a C₁₋₃ alkyl canbe combined with the embodiment in which R² is C₁₋₃ alkyl, theembodiment in which a=b=1, and the embodiment in which c=d=1. Theskilled person would understand which embodiments were mutuallyexclusive and would thus readily be able to determine the combinationsof embodiments that are contemplated by the present application.

In some embodiments of Formula I, 30-100 mol % of R^(b) represents aresidue from a diamine having Formula III

where:

-   -   R¹ and R² are the same or different at each occurrence and are        selected from the group consisting of halogen, alkyl,        fluoroalkyl, silyl, alkoxy, fluoroalkoxy, and siloxy;    -   a and b are the same or different and are an integer from 0-4;        and    -   c and d are the same or different and are 1 or 2.

All of the above-described embodiments for R¹, R², a, b, c, and d inFormula II, apply equally to R¹, R², a, b, c, and d in Formula III.

In some embodiments of Formula I, 30-100 mol % of R^(b) represents aresidue from a diamine having Formula IIIA

where R¹, R², a, b, c, and d are as defined in Formula III.

All of the above-described embodiments for R¹, R², a, b, c, and d inFormula II, apply equally to R¹, R², a, b, c, and d in Formula IIIA.

In some embodiments of Formula I, 30-100 mol % of R^(b) represents aresidue from a diamine having Formula IIIA-1

where R³ and R⁴ are as defined in Formula IIA-1.

All of the above-described embodiments for R³ and R⁴ in Formula IIA-1,apply equally to R³ and R⁴ in Formula IIIA-1.

In some embodiments of Formula I, 30-100 mol % of R^(b) represents aresidue from a diamine having Formula IIIB

where R¹, R², a, b, c, and d are as defined in Formula Ill.

All of the above-described embodiments for R¹, R², a, b, c, and d inFormula II, apply equally to R¹, R², a, b, c, and d in Formula IIIB.

In some embodiments of Formula I, 30-100 mol % of R^(b) represents aresidue from a diamine having Formula IIIB-1

where R³ and R⁴ are as defined in Formula IIA-1.

All of the above-described embodiments for R³ and R⁴ in Formula IIA-1,apply equally to R³ and R⁴ in Formula IIIB-1.

In some embodiments of Formula I, 30-100 mol % of R^(b) represents aresidue from a diamine having a formula selected from Formula IIIC,Formula IIID, Formula IIIE, and Formula IIIF

where R¹, R², a, b, c, and d are as defined in Formula Ill.

All of the above-described embodiments for R¹, R², a, b, c, and d inFormula II, apply equally to R¹, R², a, b, c, and d in Formula IIIC,Formula IIID, Formula IIIE, and Formula IIIF.

In some embodiments of Formula I, 30-100 mol % of R^(b) represents aresidue from a diamine having a formula selected from Formula IIIC-1,Formula IIID-1, Formula IIIE-1, and Formula IIIF-1

where R³ and R⁴ are as defined in Formula IIA-1.

All of the above-described embodiments for R³ and R⁴ in Formula IIA-1,apply equally to R³ and R⁴ in Formula IIIC-1, Formula IIID-1, FormulaIIIE-1, and Formula IIIF-1.

Some examples of diamines having Formula III are shown below.

In some embodiments of Formula I, R^(b) represents a diamine residuehaving Formula II and at least one additional diamine residue.

In some embodiments of Formula I, R^(b) represents a diamine residuehaving Formula II and one additional diamine residue.

In some embodiments of Formula I, R^(b) represents a diamine residuehaving Formula II and two additional diamine residues.

In some embodiments of Formula I, R^(b) represents a diamine residuehaving Formula II and three additional diamine residues.

In some embodiments, the additional aromatic diamine is selected fromthe group consisting of p-phenylene diamine (PPD),2,2′-dimethyl-4,4′-diaminobiphenyl (m-tolidine),3,3′-dimethyl-4,4′-diaminobiphenyl (o-tolidine),3,3′-dihydroxy-4,4′-diaminobiphenyl (HAB),9,9′-bis(4-aminophenyl)fluorene (FDA), o-tolidine sulfone (TSN),2,3,5,6-tetramethyl-1,4-phenylenediamine (TMPD),2,4-diamino-1,3,5-trimethyl benzene (DAM),3,3′,5,5′-tetramethylbenzidine (3355TMB), 2,2′-bis(trifluoromethyl)benzidine (22TFMB or TFMB), 2,2-bis[4-(4-aminophenoxy)phenyl]propane(BAPP), 4,4′-methylene dianiline (MDA),4,4′-[1,3-phenylenebis(1-methyl-ethylidene)]bisaniline (Bis-M),4,4′-[1,4-phenylenebis(1-methyl-ethylidene)]bisaniline (Bis-P),4,4′-oxydianiline (4,4′-ODA), m-phenylene diamine (MPD),3,4′-oxydianiline (3,4′-ODA), 3,3′-diaminodiphenyl sulfone (3,3′-DDS),4,4′-diaminodiphenyl sulfone (4,4′-DDS), 4,4′-diaminodiphenyl sulfide(ASD), 2,2-bis[4-(4-amino-phenoxy)phenyl]sulfone (BAPS),2,2-bis[4-(3-aminophenoxy)-phenyl]sulfone (m-BAPS),1,4′-bis(4-aminophenoxy)benzene (TPE-Q), 1,3′-bis(4-aminophenoxy)benzene(TPE-R), 1,3′-bis(4-amino-phenoxy)benzene (APB-133),4,4′-bis(4-aminophenoxy)biphenyl (BAPB), 4,4′-diaminobenzanilide (DABA),methylene bis(anthranilic acid) (MBAA),1,3′-bis(4-aminophenoxy)-2,2-dimethylpropane (DANPG),1,5-bis(4-aminophenoxy)pentane (DA5MG), 2,2′-bis[4-(4-aminophenoxyphenyl)]hexafluoropropane (HFBAPP), 2,2-bis(4-aminophenyl)hexafluoropropane (Bis-A-AF), 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (Bis-AP-AF), 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane (Bis-AT-AF), 4,4′-bis(4-amino-2-trifluoromethylphenoxy)biphenyl (6BFBAPB), 3,3′5,5′-tetramethyl-4,4′-diaminodiphenylmethane (TMMDA), and the like and combinations thereof.

In some embodiments of Formula I, R^(b) represents a diamine residuehaving Formula II and at least one additional diamine residue, where theadditional aromatic diamine is selected from the group consisting ofPPD, 4,4′-ODA, 3,4′-ODA, TFMB, Bis-A-AF, Bis-AT-AF, and Bis-P.

In some embodiments of Formula I, moieties resulting from monoanhydridemonomers are present as end-capping groups.

In some embodiments, the monoanhydride monomers are selected from thegroup consisting of phthalic anhydrides and the like and derivativesthereof.

In some embodiments, the monoanhydrides are present at an amount up to 5mol % of the total tetracarboxylic acid composition.

In some embodiments of Formula I, moieties resulting from monoaminemonomers are present as end-capping groups.

In some embodiments, the monoamine monomers are selected from the groupconsisting of aniline and the like and derivatives thereof.

In some embodiments, the monoamines are present at an amount up to 5 mol% of the total amine composition.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) greater than 100,000 based on gel permeationchromatography with polystyrene standards.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) greater than 150,000 based on gel permeationchromatography with polystyrene standards.

In some embodiments, the polyamic acid has a molecular weight (M_(W))greater than 200,000 based on gel permeation chromatography withpolystyrene standards.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) greater than 250,000 based on gel permeationchromatography with polystyrene standards.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) greater than 300,000 based on gel permeationchromatography with polystyrene standards.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) between 100,000 and 400,000 based on gel permeationchromatography with polystyrene standards.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) between 200,000 and 400,000 based on gel permeationchromatography with polystyrene standards.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) between 250,000 and 350,000 based on gel permeationchromatography with polystyrene standards.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) between 200,000 and 300,000 based on gel permeationchromatography with polystyrene standards.

Any of the above embodiments for the polyamic acid can be combined withone or more of the other embodiments, so long as they are not mutuallyexclusive. For example, the embodiment in which R^(a) represents a PMDAresidue can be combined with the embodiments in which R^(b) has FormulaIIB-1.

Overall polyamic acid compositions can be designated via the notationcommonly used in the art. For example, a polyamic acid having atetracarboxylic acid component that is 100% ODPA, and a diaminecomponent that is 90 mol % Bis-P and 10 mol % TFMB, would be representedas:

-   -   ODPA//Bis-P/22TFMB 100//90/10.

There is also provided a liquid composition comprising (a) the polyamicacid having a repeat unit of Formula I, and (b) a high-boiling aproticsolvent. The liquid composition is also referred to herein as the“polyamic acid solution”.

In some embodiments, the high-boiling aprotic solvent has a boilingpoint of 150° C. or higher.

In some embodiments, the high-boiling aprotic solvent has a boilingpoint of 175° C. or higher.

In some embodiments, the high-boiling aprotic solvent has a boilingpoint of 200° C. or higher.

In some embodiments, the high-boiling aprotic solvent is a polarsolvent. In some embodiments, the solvent has a dielectric constantgreater than 20.

Some examples of high-boiling aprotic solvents include, but are notlimited to, N-methyl-2-pyrrolidone (NMP), dimethyl acetamide (DMAc),dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), γ-butyrolactone,dibutyl carbitol, butyl carbitol acetate, diethylene glycol monoethylether acetate, propylene glycol monomethyl ether acetate and the like,and combinations thereof.

In some embodiments of the liquid composition, the solvent is selectedfrom the group consisting of NMP, DMAc, and DMF.

In some embodiments of the liquid composition, the solvent is NMP.

In some embodiments of the liquid composition, the solvent is DMAc.

In some embodiments of the liquid composition, the solvent is DMF.

In some embodiments of the liquid composition, the solvent isγ-butyrolactone.

In some embodiments of the liquid composition, the solvent is dibutylcarbitol.

In some embodiments of the liquid composition, the solvent is butylcarbitol acetate.

In some embodiments of the liquid composition, the solvent is diethyleneglycol monoethyl ether acetate.

In some embodiments of the liquid composition, the solvent is propyleneglycol monoethyl ether acetate.

In some embodiments, more than one of the high-boiling aprotic solventsidentified above is used in the liquid composition.

In some embodiments, additional cosolvents are used in the liquidcomposition.

In some embodiments, the liquid composition is <1 weight % polyamic acidin >99 weight % high-boiling aprotic solvent.

In some embodiments, the liquid composition is 1-5 weight % polyamicacid in 95-99 weight % high-boiling aprotic solvent.

In some embodiments, the liquid composition is 5-10 weight % polyamicacid in 90-95 weight % high-boiling aprotic solvent.

In some embodiments, the liquid composition is 10-15 weight % polyamicacid in 85-90 weight % high-boiling aprotic solvent.

In some embodiments, the liquid composition is 15-20 weight % polyamicacid in 80-85 weight % high-boiling aprotic solvent.

In some embodiments, the liquid composition is 20-25 weight % polyamicacid in 75-80 weight % high-boiling aprotic solvent.

In some embodiments, the liquid composition is 25-30 weight % polyamicacid in 70-75 weight % high-boiling aprotic solvent.

In some embodiments, the liquid composition is 30-35 weight % polyamicacid in 65-70 weight % high-boiling aprotic solvent.

In some embodiments, the liquid composition is 35-40 weight % polyamicacid in 60-65 weight % high-boiling aprotic solvent.

In some embodiments, the liquid composition is 40-45 weight % polyamicacid in 55-60 weight % high-boiling aprotic solvent.

In some embodiments, the liquid composition is 45-50 weight % polyamicacid in 50-55 weight % high-boiling aprotic solvent.

In some embodiments, the liquid composition is 50 weight % polyamic acidin 50 weight % high-boiling aprotic solvent.

The polyamic acid solutions can optionally further contain any one of anumber of additives. Such additives can be: antioxidants, heatstabilizers, adhesion promoters, coupling agents (e.g. silanes),inorganic fillers or various reinforcing agents so long as they don'tadversely impact the desired polyimide properties.

The polyamic acid solutions can be prepared using a variety of availablemethods with respect to the introduction of the components (i.e., themonomers and solvents). Some methods of producing a polyamic acidsolution include:

-   -   (a) a method wherein the diamine components and dianhydride        components are preliminarily mixed together and then the mixture        is added in portions to a solvent while stirring.    -   (b) a method wherein a solvent is added to a stirring mixture of        diamine and dianhydride components. (contrary to (a) above)    -   (c) a method wherein diamines are exclusively dissolved in a        solvent and then dianhydrides are added thereto at such a ratio        as allowing to control the reaction rate.    -   (d) a method wherein the dianhydride components are exclusively        dissolved in a solvent and then amine components are added        thereto at such a ratio to allow control of the reaction rate.    -   (e) a method wherein the diamine components and the dianhydride        components are separately dissolved in solvents and then these        solutions are mixed in a reactor.    -   (f) a method wherein the polyamic acid with excessive amine        component and another polyamic acid with excessive dianhydride        component are preliminarily formed and then reacted with each        other in a reactor, particularly in such a way as to create a        non-random or block copolymer.    -   (g) a method wherein a specific portion of the amine components        and the dianhydride components are first reacted and then the        residual diamine components are reacted, or vice versa.    -   (h) a method wherein the components are added in part or in        whole in any order to either part or whole of the solvent, also        where part or all of any component can be added as a solution in        part or all of the solvent.    -   (i) a method of first reacting one of the dianhydride components        with one of the diamine components giving a first polyamic acid.        Then reacting the other dianhydride component with the other        amine component to give a second polyamic acid. Then combining        the polyamic acids in any one of a number of ways prior to film        formation.        Generally speaking, a polyamic acid solution can be obtained        from any one of the polyamic acid solution preparation methods        disclosed above.

The polyamic acid solution can then be filtered one or more times inorder to reduce the particle content. The polyimide film generated fromsuch a filtered solution can show a reduced number of defects andthereby lead to superior performance in the electronics applicationsdisclosed herein. An assessment of the filtration efficiency can be madeby the laser particle counter test wherein a representative sample ofthe polyamic acid solution is cast onto a 5″ silicon wafer. After softbaking/drying, the film is evaluated for particle content by any numberof laser particle counting techniques on instruments that arecommercially available and known in the art.

In some embodiments, the polyamic acid solution is prepared and filteredto yield a particle content of less than 40 particles as measured by thelaser particle counter test.

In some embodiments, the polyamic acid solution is prepared and filteredto yield a particle content of less than 30 particles as measured by thelaser particle counter test.

In some embodiments, the polyamic acid solution is prepared and filteredto yield a particle content of less than 20 particles as measured by thelaser particle counter test.

In some embodiments, the polyamic acid solution is prepared and filteredto yield a particle content of less than 10 particles as measured by thelaser particle counter test.

In some embodiments, the polyamic acid solution is prepared and filteredto yield particle content of between 2 particles and 8 particles asmeasured by the laser particle counter test.

In some embodiments, the polyamic acid solution is prepared and filteredto yield particle content of between 4 particles and 6 particles asmeasured by the laser particle counter test.

Exemplary preparations of polyamic acid solutions are given in theexamples.

3. Polyimide Having the Repeat Unit Structure of Formula IV

There are provided a polyimide having a repeat unit structure of FormulaIV

where

-   -   R^(a) is the same or different at each occurrence and represents        one or more tetracarboxylic acid component residues, and    -   R^(b) is the same or different at each occurrence and represents        one or more aromatic diamine residues;        wherein 30-100 mol % of R^(b) has Formula II

where:

-   -   R¹ and R² are the same or different at each occurrence and are        selected from the group consisting of halogen, alkyl,        fluoroalkyl, silyl, alkoxy, fluoroalkoxy, and siloxy;    -   a and b are the same or different and are an integer from 0-4;    -   c and d are the same or different and are 1 or 2; and    -   * indicates a point of attachment.

All of the above-described embodiments for R^(a) and R^(b) in Formula Iapply equally to R^(a) and R^(b) in Formula IV.

All of the above-described embodiments for R¹, R², a, b, c, and d inFormula II as applied to Formula I, apply equally to R¹, R², a, b, c,and d in Formula II as applied to Formula IV.

Polyimides can be made from any suitable polyimide precursor such as apolyamic acid, a polyamic acid ester, a polyisoimide, and a polyamicacid salt.

There is also provided a polyimide film, wherein the polyimide has arepeat unit structure of Formula IV, as described above.

Polyimide films can be made by coating a polyimide precursor onto asubstrate and subsequently imidizing. This can be accomplished by athermal conversion process or a chemical conversion process.

Further, if the polyimide is soluble in suitable coating solvents, itcan be provided as an already-imidized polymer dissolved in the suitablecoating solvent and coated as the polyimide.

In some embodiments of the polyimide film, the in-plane coefficient ofthermal expansion (CTE) is less than 45 ppm/° C. between 50° C. and 200°C.; in some embodiments, less than 30 ppm/° C.; in some embodiments,less than 20 ppm/° C.; in some embodiments, less than 10 ppm/° C.; insome embodiments, less than 5 ppm/° C.; in some embodiments, between 0ppm/° C. and 15 ppm/° C.; in some embodiments, between 0 ppm/° C. and 10ppm/° C.; in some embodiments, between 0 ppm/° C. and 5 ppm/° C.

In some embodiments of the polyimide film, the glass transitiontemperature (T_(g)) is greater than 250° C. for a polyimide film curedat a temperature above 300° C.; in some embodiments, greater than 300°C.; in some embodiments, greater than 350° C.

In some embodiments of the polyimide film, the 1% TGA weight losstemperature is greater than 350° C.; in some embodiments, greater than400° C.; in some embodiments, greater than 450° C.

In some embodiments of the polyimide film, the tensile modulus isbetween 1.5 GPa and 15.0 GPa; in some embodiments, between 1.5 GPa and12.0 GPa.

In some embodiments of the polyimide film, the elongation to break isgreater than 10%.

In some embodiments of the polyimide film, the birefringence at 633 nmis less than 0.15; in some embodiments, less than 0.10; in someembodiments, less than 0.05.

In some embodiments of the polyimide film, the haze is less than 1.0%;in some embodiments less than 0.5%.

In some embodiments of the polyimide film, the transmittance at 400 nmis greater than 40%; in some embodiments, greater than 50%; in someembodiments, greater than 60%.

In some embodiments of the polyimide film, the transmittance at 430 nmis greater than 60%; in some embodiments, greater than 70%.

In some embodiments of the polyimide film, the transmittance at 450 nmis greater than 70%; in some embodiments, greater than 80%.

In some embodiments of the polyimide film, the transmittance at 550 nmis greater than 70%; in some embodiments, greater than 80%.

In some embodiments of the polyimide film, the transmittance at 750 nmis greater than 70%; in some embodiments, greater than 80%; in someembodiments, greater than 90%.

Any of the above embodiments for the polyimide film can be combined withone or more of the other embodiments, so long as they are not mutuallyexclusive.

4. Methods for Preparing the Polyimide Films

Generally, polyimide films can be prepared from polyimide precursors bychemical or thermal conversion. In some embodiments, the films areprepared from the corresponding polyamic acid solutions by chemical orthermal conversion processes. The polyimide films disclosed herein,particularly when used as flexible replacements for glass in electronicdevices, are prepared by thermal conversion processes.

Generally, polyimide films can be prepared from the correspondingpolyamic acid solutions by chemical or thermal conversion processes. Thepolyimide films disclosed herein, particularly when used as flexiblereplacements for glass in electronic devices, are prepared by thermalconversion or modified-thermal conversion processes, versus chemicalconversion processes.

Chemical conversion processes are described in U.S. Pat. Nos. 5,166,308and 5,298,331 which are incorporated by reference in their entirety. Insuch processes, conversion chemicals are added to the polyamic acidsolutions. The conversion chemicals found to be useful in the presentinvention include, but are not limited to, (i) one or more dehydratingagents, such as, aliphatic acid anhydrides (acetic anhydride, etc.) andacid anhydrides, and (ii) one or more catalysts, such as, aliphatictertiary amines (triethylamine, etc.), tertiary amines (dimethylaniline,etc.) and heterocyclic tertiary amines (pyridine, picoline,isoquinoline, etc.). The anhydride dehydrating material is typicallyused in a slight molar excess of the amount of amide acid groups presentin the polyamic acid solution. The amount of acetic anhydride used istypically about 2.0-3.0 moles per equivalent of the polyamic acid.Generally, a comparable amount of tertiary amine catalyst is used.

Thermal conversion processes may or may not employ conversion chemicals(i.e., catalysts) to convert a polyamic acid casting solution to apolyimide. If conversion chemicals are used, the process may beconsidered a modified-thermal conversion process. In both types ofthermal conversion processes, only heat energy is used to heat the filmto both dry the film of solvent and to perform the imidization reaction.Thermal conversion processes with or without conversion catalysts aregenerally used to prepare the polyimide films disclosed herein.

Specific method parameters are pre-selected considering that it is notjust the film composition that yields the properties of interest.Rather, the cure temperature and temperature-ramp profile also playimportant roles in the achievement of the most desirable properties forthe intended uses disclosed herein. The polyamic acids should beimidized at a temperature at, or higher than, the highest temperature ofany subsequent processing steps (e.g. deposition of inorganic or otherlayer(s) necessary to produce a functioning display), but at atemperature which is lower than the temperature at which significantthermal degradation/discoloration of the polyimide occurs. It shouldalso be noted that an inert atmosphere is generally preferred,particularly when higher processing temperatures are employed forimidization.

For the polyamic acids/polyimides disclosed herein, temperatures of 300°C. to 320° C. are typically employed when subsequent processingtemperatures in excess of 300° C. are required. Choosing the propercuring temperature allows a fully cured polyimide which achieves thebest balance of thermal and mechanical properties. Because of this veryhigh temperature, an inert atmosphere is required. Typically, oxygenlevels in the oven of <100 ppm should be employed. Very low oxygenlevels enable the highest curing temperatures to be used withoutsignificant degradation/discoloration of the polymer. Catalysts thataccelerate the imidization process are effective at achieving higherlevels of imidization at cure temperatures between about 200° C. and300° C. This approach may be optionally employed if the flexible deviceis prepared with upper cure temperatures that are below the T_(g) of thepolyimide.

The amount of time in each potential cure step is also an importantprocess consideration. Generally, the time used for thehighest-temperature curing should be kept to a minimum. For 320° C.cure, for example, cure time can be up to an hour or so under an inertatmosphere, but at higher cure temperatures, this time should beshortened to avoid thermal degradation. Generally speaking, highertemperature dictates shorter time. Those skilled in the art willrecognize the balance between temperature and time in order to optimizethe properties of the polyimide for a particular end use.

In some embodiments, the polyamic acid solution is converted into apolyimide film via a thermal conversion process.

In some embodiments of the thermal conversion process, the polyamic acidsolution is coated onto the matrix such that the soft-baked thickness ofthe resulting film is less than 50 μm.

In some embodiments of the thermal conversion process, the polyamic acidsolution is coated onto the matrix such that the soft-baked thickness ofthe resulting film is less than 40 μm.

In some embodiments of the thermal conversion process, the polyamic acidsolution is coated onto the matrix such that the soft-baked thickness ofthe resulting film is less than 30 μm.

In some embodiments of the thermal conversion process, the polyamic acidsolution is coated onto the matrix such that the soft-baked thickness ofthe resulting film is less than 20 μm.

In some embodiments of the thermal conversion process, the polyamic acidsolution is coated onto the matrix such that the soft-baked thickness ofthe resulting film is between 10 μm and 20 μm.

In some embodiments of the thermal conversion process, the polyamic acidsolution is coated onto the matrix such that the soft-baked thickness ofthe resulting film is between 15 μm and 20 μm.

In some embodiments of the thermal conversion process, the polyamic acidsolution is coated onto the matrix such that the soft-baked thickness ofthe resulting film is 18 μm.

In some embodiments of the thermal conversion process, the polyamic acidsolution is coated onto the matrix such that the soft-baked thickness ofthe resulting film is less than 10 μm.

In some embodiments of the thermal conversion process, the coated matrixis soft baked on a hot plate in proximity mode wherein nitrogen gas isused to hold the coated matrix just above the hot plate.

In some embodiments of the thermal conversion process, the coated matrixis soft baked on a hot plate in full-contact mode wherein the coatedmatrix is in direct contact with the hot plate surface.

In some embodiments of the thermal conversion process, the coated matrixis soft baked on a hot plate using a combination of proximity andfull-contact modes.

In some embodiments of the thermal conversion process, the coated matrixis soft-baked using a hot plate set at 80° C.

In some embodiments of the thermal conversion process, the coated matrixis soft-baked using a hot plate set at 90° C.

In some embodiments of the thermal conversion process, the coated matrixis soft-baked using a hot plate set at 100° C.

In some embodiments of the thermal conversion process, the coated matrixis soft-baked using a hot plate set at 110° C.

In some embodiments of the thermal conversion process, the coated matrixis soft-baked using a hot plate set at 120° C.

In some embodiments of the thermal conversion process, the coated matrixis soft-baked using a hot plate set at 130° C.

In some embodiments of the thermal conversion process, the coated matrixis soft-baked using a hot plate set at 140° C.

In some embodiments of the thermal conversion process, the coated matrixis soft-baked for a total time of more than 10 minutes.

In some embodiments of the thermal conversion process, the coated matrixis soft-baked for a total time of less than 10 minutes.

In some embodiments of the thermal conversion process, the coated matrixis soft-baked for a total time of less than 8 minutes.

In some embodiments of the thermal conversion process, the coated matrixis soft-baked for a total time of less than 6 minutes.

In some embodiments of the thermal conversion process, the coated matrixis soft-baked for a total time of 4 minutes.

In some embodiments of the thermal conversion process, the coated matrixis soft-baked for a total time of less than 4 minutes.

In some embodiments of the thermal conversion process, the coated matrixis soft-baked for a total time of less than 2 minutes.

In some embodiments of the thermal conversion process, the soft-bakedcoated matrix is subsequently cured at 2 pre-selected temperatures for 2pre-selected time intervals, the latter of which may be the same ordifferent.

In some embodiments of the thermal conversion process, the soft-bakedcoated matrix is subsequently cured at 3 pre-selected temperatures for 3pre-selected time intervals, each of which of the latter of which may bethe same or different.

In some embodiments of the thermal conversion process, the soft-bakedcoated matrix is subsequently cured at 4 pre-selected temperatures for 4pre-selected time intervals, each of which of the latter of which may bethe same or different.

In some embodiments of the thermal conversion process, the soft-bakedcoated matrix is subsequently cured at 5 pre-selected temperatures for 5pre-selected time intervals, each of which of the latter of which may bethe same or different.

In some embodiments of the thermal conversion process, the soft-bakedcoated matrix is subsequently cured at 6 pre-selected temperatures for 6pre-selected time intervals, each of which of the latter of which may bethe same or different.

In some embodiments of the thermal conversion process, the soft-bakedcoated matrix is subsequently cured at 7 pre-selected temperatures for 7pre-selected time intervals, each of which of the latter of which may bethe same or different.

In some embodiments of the thermal conversion process the soft-bakedcoated matrix is subsequently cured at 8 pre-selected temperatures for 8pre-selected time intervals, each of which of the latter of which may bethe same or different.

In some embodiments of the thermal conversion process, the soft-bakedcoated matrix is subsequently cured at 9 pre-selected temperatures for 9pre-selected time intervals, each of which of the latter of which may bethe same or different.

In some embodiments of the thermal conversion process, the soft-bakedcoated matrix is subsequently cured at 10 pre-selected temperatures for10 pre-selected time intervals, each of which of the latter of which maybe the same or different.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 80° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 100° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 100° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 150° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 150° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 200° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 200° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 250° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 250° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 300° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 300° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 350° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 350° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 400° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 400° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 450° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 450° C.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 2 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 5 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 10 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 15 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 20 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 25 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 30 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 35 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 40 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 45 minutes.

In some of the thermal conversion process, one or more of thepre-selected time intervals is 50 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 55 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 60 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is greater than 60 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is between 2 minutes and 60 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is between 2 minutes and 90 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is between 2 minutes and 120 minutes.

In some embodiments of the thermal conversion process, the method forpreparing a polyimide film comprises the following steps in order:coating the above-described polyamic acid solution onto a matrix;soft-baking the coated matrix; treating the soft-baked coated matrix ata plurality of pre-selected temperatures for a plurality of pre-selectedtime intervals whereby the polyimide film exhibits properties that aresatisfactory for use in electronics applications like those disclosedherein.

In some embodiments of the thermal conversion process, the method forpreparing a polyimide film consists of the following steps in order:coating the above-described polyamic acid solution onto a matrix;soft-baking the coated matrix; treating the soft-baked coated matrix ata plurality of pre-selected temperatures for a plurality of pre-selectedtime intervals whereby the polyimide film exhibits properties that aresatisfactory for use in electronics applications like those disclosedherein.

In some embodiments of the thermal conversion process, the method forpreparing a polyimide film consists essentially of the following stepsin order: coating the above-described polyamic acid solution onto amatrix; soft-baking the coated matrix; treating the soft-baked coatedmatrix at a plurality of pre-selected temperatures for a plurality ofpre-selected time intervals whereby the polyimide film exhibitsproperties that are satisfactory for use in electronics applicationslike those disclosed herein.

Typically, the polyamic acid solutions/polyimides disclosed herein arecoated/cured onto a supporting glass substrate to facilitate theprocessing through the rest of the display making process. At some pointin the process as determined by the display maker, the polyimide coatingis removed from the supporting glass substrate by a mechanical or laserlift off process. These processes separate the polyimide as a film withthe deposited display layers from the glass and enable a flexibleformat. Often, this polyimide film with deposition layers is then bondedto a thicker, but still flexible, plastic film to provide support forsubsequent fabrication of the display.

There are also provided modified-thermal conversion processes whereinconversion catalysts generally cause imidization reactions to run atlower temperatures than would be possible in the absence of suchconversion catalysts.

In some embodiments, the polyamic acid solution is converted into apolyimide film via a modified-thermal conversion process.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains conversion catalysts.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains conversion catalysts selectedfrom the group consisting of tertiary amines.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains conversion catalysts selectedfrom the group consisting of tributylamine, dimethylethanolamine,isoquinoline, 1,2-dimethylimidazole, N-methylimidazole,2-methylimidazole, 2-ethyl-4-imidazole, 3,5-dimethylpyridine,3,4-dimethylpyridine, 2,5-dimethylpyridine, 5-methylbenzimidazole, andthe like.

In some embodiments of the modified-thermal conversion process, theconversion catalyst is present at 5 weight percent or less of thepolyamic acid solution.

In some embodiments of the modified-thermal conversion process, theconversion catalyst is present at 3 weight percent or less of thepolyamic acid solution.

In some embodiments of the modified-thermal conversion process, theconversion catalyst is present at 1 weight percent or less of thepolyamic acid solution.

In some embodiments of the modified-thermal conversion process, theconversion catalyst is present at 1 weight percent of the polyamic acidsolution.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains tributylamine as a conversioncatalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains dimethylethanolamine as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains isoquinoline as a conversioncatalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains 1,2-dimethylimidazole as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains 3,5-dimethylpyridine as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains 5-methylbenzimidazole as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains N-methylimidazole as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains 2-methylimidazole as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains 2-ethyl-4-imidazole as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains 3,4-dimethylpyridine as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains 2,5-dimethylpyridine as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is coated onto the matrix such that thesoft-baked thickness of the resulting film is less than 50 μm.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is coated onto the matrix such that thesoft-baked thickness of the resulting film is less than 40 μm.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is coated onto the matrix such that thesoft-baked thickness of the resulting film is less than 30 μm.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is coated onto the matrix such that thesoft-baked thickness of the resulting film is less than 20 μm.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is coated onto the matrix such that thesoft-baked thickness of the resulting film is between 10 μm and 20 μm.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is coated onto the matrix such that thesoft-baked thickness of the resulting film is between 15 μm and 20 μm.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is coated onto the matrix such that thesoft-baked thickness of the resulting film is 18 μm.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is coated onto the matrix such that thesoft-baked thickness of the resulting film is less than 10 μm.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft baked on a hot plate in proximity mode whereinnitrogen gas is used to hold the coated matrix just above the hot plate.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft baked on a hot plate in full-contact mode whereinthe coated matrix is in direct contact with the hot plate surface.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft baked on a hot plate using a combination ofproximity and full-contact modes.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft-baked using a hot plate set at 80° C.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft-baked using a hot plate set at 90° C.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft-baked using a hot plate set at 100° C.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft-baked using a hot plate set at 110° C.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft-baked using a hot plate set at 120° C.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft-baked using a hot plate set at 130° C.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft-baked using a hot plate set at 140° C.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft-baked for a total time of more than 10 minutes.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft-baked for a total time of less than 10 minutes.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft-baked for a total time of less than 8 minutes.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft-baked for a total time of less than 6 minutes.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft-baked for a total time of 4 minutes.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft-baked for a total time of less than 4 minutes.

In some embodiments of the modified-thermal conversion process, thecoated matrix is soft-baked for a total time of less than 2 minutes.

In some embodiments of the modified-thermal conversion process, thesoft-baked coated matrix is subsequently cured at 2 pre-selectedtemperatures for 2 pre-selected time intervals, the latter of which maybe the same or different.

In some embodiments of the modified-thermal conversion process, thesoft-baked coated matrix is subsequently cured at 3 pre-selectedtemperatures for 3 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process, thesoft-baked coated matrix is subsequently cured at 4 pre-selectedtemperatures for 4 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process, thesoft-baked coated matrix is subsequently cured at 5 pre-selectedtemperatures for 5 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process, thesoft-baked coated matrix is subsequently cured at 6 pre-selectedtemperatures for 6 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process, thesoft-baked coated matrix is subsequently cured at 7 pre-selectedtemperatures for 7 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process thesoft-baked coated matrix is subsequently cured at 8 pre-selectedtemperatures for 8 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process, thesoft-baked coated matrix is subsequently cured at 9 pre-selectedtemperatures for 9 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process, thesoft-baked coated matrix is subsequently cured at 10 pre-selectedtemperatures for 10 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 80° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 100° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 100° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 150° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 150° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 200° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 200° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 220° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 220° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 230° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 230° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 240° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 240° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 250° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 250° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 260° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 260° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 270° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 270° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 280° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 280° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 290° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 290° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 300° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is less than 300° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is less than 290° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is less than 280° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is less than 270° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is less than 260° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is less than 250° C.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 2 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 5 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 10 minutes.

In some embodiments of the modified-conversion process, one or more ofthe pre-selected time intervals is 15 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 20 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 25 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 30 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 35 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 40 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 45 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 50 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 55 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 60 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is greater than 60 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is between 2 minutes and 60minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is between 2 minutes and 90minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is between 2 minutes and 120minutes.

In some embodiments of the modified-thermal conversion process, themethod for preparing a polyimide film comprises the following steps inorder: coating the above-described polyamic acid solution including aconversion chemical onto a matrix; soft-baking the coated matrix;treating the soft-baked coated matrix at a plurality of pre-selectedtemperatures for a plurality of pre-selected time intervals whereby thepolyimide film exhibits properties that are satisfactory for use inelectronics applications like those disclosed herein.

In some embodiments of the modified-thermal conversion process, themethod for preparing a polyimide film consists of the following steps inorder: coating the above-described polyamic acid solution including aconversion chemical onto a matrix; soft-baking the coated matrix;treating the soft-baked coated matrix at a plurality of pre-selectedtemperatures for a plurality of pre-selected time intervals whereby thepolyimide film exhibits properties that are satisfactory for use inelectronics applications like those disclosed herein.

In some embodiments of the modified-thermal conversion process, themethod for preparing a polyimide film consists essentially of thefollowing steps in order: coating the above-described polyamic acidsolution including a conversion chemical onto a matrix; soft-baking thecoated matrix; treating the soft-baked coated matrix at a plurality ofpre-selected temperatures for a plurality of pre-selected time intervalswhereby the polyimide film exhibits properties that are satisfactory foruse in electronics applications like those disclosed herein.

5. The Electronic Device

The polyimide films disclosed herein can be suitable for use in a numberof layers in electronic display devices such as OLED and LCD Displays.Nonlimiting examples of such layers include device substrates, touchpanels, substrates for color filter sheets, cover films, and others. Theparticular materials' properties requirements for each application areunique and may be addressed by appropriate composition(s) and processingcondition(s) for the polyimide films disclosed herein.

In some embodiments, the flexible replacement for glass in an electronicdevice is a polyimide film having the repeat unit of Formula IV, asdescribed in detail above.

In some embodiments, there is provided an organic electronic devicehaving at least one layer comprising a polyimide film having a repeatunit of Formula IV, as described in detail above.

Organic electronic devices that may benefit from having one or morelayers including at least one compound as described herein include, butare not limited to, (1) devices that convert electrical energy intoradiation (e.g., a light-emitting diode, light emitting diode display,lighting device, luminaire, or diode laser), (2) devices that detectsignals through electronics processes (e.g., photodetectors,photoconductive cells, photoresistors, photoswitches, phototransistors,phototubes, IR detectors, biosensors), (3) devices that convertradiation into electrical energy, (e.g., a photovoltaic device or solarcell), (4) devices that convert light of one wavelength to light of alonger wavelength, (e.g., a down-converting phosphor device); and (5)devices that include one or more electronic components that include oneor more organic semi-conductor layers (e.g., a transistor or diode).Other uses for the compositions according to the present inventioninclude coating materials for memory storage devices, antistatic films,biosensors, electrochromic devices, solid electrolyte capacitors, energystorage devices such as a rechargeable battery, and electromagneticshielding applications.

One illustration of a polyimide film that can act as a flexiblereplacement for glass as described herein is shown in FIG. 1. Theflexible film 100 can have the properties as described in theembodiments of this disclosure. In some embodiments, the polyimide filmthat can act as a flexible replacement for glass is included in anelectronic device. FIG. 2 illustrates the case when the electronicdevice 200 is an organic electronic device. The device 200 has asubstrate 100, an anode layer 110 and a second electrical contact layer,a cathode layer 130, and a photoactive layer 120 between them.Additional layers may optionally be present. Adjacent to the anode maybe a hole injection layer (not shown), sometimes referred to as a bufferlayer. Adjacent to the hole injection layer may be a hole transportlayer (not shown), including hole transport material. Adjacent to thecathode may be an electron transport layer (not shown), including anelectron transport material. As an option, devices may use one or moreadditional hole injection or hole transport layers (not shown) next tothe anode 110 and/or one or more additional electron injection orelectron transport layers (not shown) next to the cathode 130. Layersbetween 110 and 130 are individually and collectively referred to as theorganic active layers. Additional layers that may or may not be presentinclude color filters, touch panels, and/or cover sheets. One or more ofthese layers, in addition to the substrate 100, may also be made fromthe polyimide films disclosed herein.

The different layers will be discussed further herein with reference toFIG. 2. However, the discussion applies to other configurations as well.

In some embodiments, the different layers have the following range ofthicknesses: substrate 100, 5-100 microns, anode 110, 500-5000 Å, insome embodiments, 1000-2000 Å; hole injection layer (not shown), 50-2000Å, in some embodiments, 200-1000 Å; hole transport layer (not shown),50-3000 Å, in some embodiments, 200-2000 Å; photoactive layer 120,10-2000 Å, in some embodiments, 100-1000 Å; electron transport layer(not shown), 50-2000 Å, in some embodiments, 100-1000 Å; cathode 130,200-10000 Å, in some embodiments, 300-5000 Å. The desired ratio of layerthicknesses will depend on the exact nature of the materials used.

In some embodiments, the organic electronic device (OLED) contains aflexible replacement for glass as disclosed herein.

In some embodiments, an organic electronic device includes a substrate,an anode, a cathode, and a photoactive layer therebetween, and furtherincludes one or more additional organic active layers. In someembodiments, the additional organic active layer is a hole transportlayer. In some embodiments, the additional organic active layer is anelectron transport layer. In some embodiments, the additional organiclayers are both hole transport and electron transport layers.

The anode 110 is an electrode that is particularly efficient forinjecting positive charge carriers. It can be made of, for examplematerials containing a metal, mixed metal, alloy, metal oxide ormixed-metal oxide, or it can be a conducting polymer, and mixturesthereof. Suitable metals include the Group 11 metals, the metals inGroups 4, 5, and 6, and the Group 8-10 transition metals. If the anodeis to be light-transmitting, mixed-metal oxides of Groups 12, 13 and 14metals, such as indium-tin-oxide, are generally used. The anode may alsoinclude an organic material such as polyaniline as described in“Flexible light-emitting diodes made from soluble conducting polymer,”Nature vol. 357, pp 477 479 (11 Jun. 1992). At least one of the anodeand cathode should be at least partially transparent to allow thegenerated light to be observed.

Optional hole injection layers can include hole injection materials. Theterm “hole injection layer” or “hole injection material” is intended tomean electrically conductive or semiconductive materials and may haveone or more functions in an organic electronic device, including but notlimited to, planarization of the underlying layer, charge transportand/or charge injection properties, scavenging of impurities such asoxygen or metal ions, and other aspects to facilitate or to improve theperformance of the organic electronic device. Hole injection materialsmay be polymers, oligomers, or small molecules, and may be in the formof solutions, dispersions, suspensions, emulsions, colloidal mixtures,or other compositions.

The hole injection layer can be formed with polymeric materials, such aspolyaniline (PANI) or polyethylenedioxythiophene (PEDOT), which areoften doped with protonic acids. The protonic acids can be, for example,poly(styrenesulfonic acid), poly(2-acrylamido-2-methyl-1-propanesulfonicacid), and the like. The hole injection layer 120 can include chargetransfer compounds, and the like, such as copper phthalocyanine and thetetrathiafulvalene-tetracyanoquinodimethane system (TTF-TCNQ). In someembodiments, the hole injection layer 120 is made from a dispersion of aconducting polymer and a colloid-forming polymeric acid. Such materialshave been described in, for example, published U.S. patent applications2004-0102577, 2004-0127637, and 2005-0205860.

Other layers can include hole transport materials. Examples of holetransport materials for the hole transport layer have been summarizedfor example, in Kirk-Othmer Encyclopedia of Chemical Technology, FourthEdition, Vol. 18, p. 837-860, 1996, by Y. Wang. Both hole transportingsmall molecules and polymers can be used. Commonly used holetransporting molecules include, but are not limited to:4,4′,4″-tris(N,N-diphenyl-amino)-triphenylamine (TDATA);4,4′,4″-tris(N-3-methylphenyl-N-phenyl-amino)-triphenylamine (MTDATA);N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine(TPD); 4, 4′-bis(carbazol-9-yl)biphenyl (CBP);1,3-bis(carbazol-9-yl)benzene (mCP); 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC);N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-[1,1′-(3,3′-dimethyl)biphenyl]-4,4′-diamine(ETPD); tetrakis-(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine (PDA);α-phenyl-4-N,N-diphenylaminostyrene (TPS); p-(diethylamino)benzaldehydediphenylhydrazone (DEH); triphenylamine (TPA);bis[4-(N,N-diethylamino)-2-methylphenyl](4-methylphenyl)methane (MPMP);1-phenyl-3-[p-(diethylamino)styryl]-5-[p-(diethylamino)phenyl]pyrazoline (PPR or DEASP); 1,2-trans-bis(9H-carbazol-9-yl)cyclobutane(DCZB); N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine(TTB); N,N′-bis(naphthalen-1-yl)-N,N′-bis-(phenyl)benzidine (α-NPB); andporphyrinic compounds, such as copper phthalocyanine. Commonly used holetransporting polymers include, but are not limited to,polyvinylcarbazole, (phenylmethyl)polysilane, poly(dioxythiophenes),polyanilines, and polypyrroles. It is also possible to obtain holetransporting polymers by doping hole transporting molecules such asthose mentioned above into polymers such as polystyrene andpolycarbonate. In some cases, triarylamine polymers are used, especiallytriarylamine-fluorene copolymers. In some cases, the polymers andcopolymers are crosslinkable. Examples of crosslinkable hole transportpolymers can be found in, for example, published US patent application2005-0184287 and published PCT application WO 2005/052027. In someembodiments, the hole transport layer is doped with a p-dopant, such astetrafluorotetracyanoquinodimethane andperylene-3,4,9,10-tetracarboxylic-3,4,9,10-dianhydride.

Depending upon the application of the device, the photoactive layer 120can be a light-emitting layer that is activated by an applied voltage(such as in a light-emitting diode or light-emitting electrochemicalcell), a layer of material that absorbs light and emits light having alonger wavelength (such as in a down-converting phosphor device), or alayer of material that responds to radiant energy and generates a signalwith or without an applied bias voltage (such as in a photodetector orphotovoltaic device).

In some embodiments, the photoactive layer includes a compoundcomprising an emissive compound having as a photoactive material. Insome embodiments, the photoactive layer further comprises a hostmaterial. Examples of host materials include, but are not limited to,chrysenes, phenanthrenes, triphenylenes, phenanthrolines, naphthalenes,anthracenes, quinolines, isoquinolines, quinoxalines, phenylpyridines,carbazoles, indolocarbazoles, furans, benzofurans, dibenzofurans,benzodifurans, and metal quinolinate complexes. In some embodiments, thehost materials are deuterated.

In some embodiments, the photoactive layer comprises (a) a dopantcapable of electroluminescence having an emission maximum between 380and 750 nm, (b) a first host compound, and (c) a second host compound.Suitable second host compounds are described above.

In some embodiments, the photoactive layer includes only (a) a dopantcapable of electroluminescence having an emission maximum between 380and 750 nm, (b) a first host compound, and (c) a second host compound,where additional materials that would materially alter the principle ofoperation or the distinguishing characteristics of the layer are notpresent.

In some embodiments, the first host is present in higher concentrationthan the second host, based on weight in the photoactive layer.

In some embodiments, the weight ratio of first host to second host inthe photoactive layer is in the range of 10:1 to 1:10. In someembodiments, the weight ratio is in the range of 6:1 to 1:6; in someembodiments, 5:1 to 1:2; in some embodiments, 3:1 to 1:1.

In some embodiments, the weight ratio of dopant to the total host is inthe range of 1:99 to 20:80; in some embodiments, 5:95 to 15:85.

In some embodiments, the photoactive layer comprises (a) a redlight-emitting dopant, (b) a first host compound, and (c) a second hostcompound.

In some embodiments, the photoactive layer comprises (a) a greenlight-emitting dopant, (b) a first host compound, and (c) a second hostcompound.

In some embodiments, the photoactive layer comprises (a) a yellowlight-emitting dopant, (b) a first host compound, and (c) a second hostcompound.

Optional layers can function both to facilitate electron transport, andalso serve as a confinement layer to prevent quenching of the exciton atlayer interfaces. Preferably, this layer promotes electron mobility andreduces exciton quenching.

In some embodiments, such layers include other electron transportmaterials. Examples of electron transport materials which can be used inthe optional electron transport layer, include metal chelated oxinoidcompounds, including metal quinolate derivatives such astris(8-hydroxyquinolato)aluminum (AIQ),bis(2-methyl-8-quinolinolato)(p-phenylphenolato) aluminum (BAIq),tetrakis-(8-hydroxyquinolato)hafnium (HfQ) andtetrakis-(8-hydroxyquinolato)zirconium (ZrQ); and azole compounds suchas 2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD),3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole (TAZ), and1,3,5-tri(phenyl-2-benzimidazole)benzene (TPBI); quinoxaline derivativessuch as 2,3-bis(4-fluorophenyl)quinoxaline; phenanthrolines such as4,7-diphenyl-1,10-phenanthroline (DPA) and2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (DDPA); triazines;fullerenes; and mixtures thereof. In some embodiments, the electrontransport material is selected from the group consisting of metalquinolates and phenanthroline derivatives. In some embodiments, theelectron transport layer further includes an n-dopant. N-dopantmaterials are well known. The n-dopants include, but are not limited to,Group 1 and 2 metals; Group 1 and 2 metal salts, such as LiF, CsF, andCs₂CO₃; Group 1 and 2 metal organic compounds, such as Li quinolate; andmolecular n-dopants, such as leuco dyes, metal complexes, such asW₂(hpp)₄ where hpp=1,3,4,6,7,8-hexahydro-2H-pyrimido-[1,2-a]-pyrimidineand cobaltocene, tetrathianaphthacene,bis(ethylenedithio)tetrathiafulvalene, heterocyclic radicals ordiradicals, and the dimers, oligomers, polymers, dispiro compounds andpolycycles of heterocyclic radical or diradicals.

An optional electron injection layer may be deposited over the electrontransport layer. Examples of electron injection materials include, butare not limited to, Li-containing organometallic compounds, LiF, Li₂O,Li quinolate, Cs-containing organometallic compounds, CsF, Cs₂O, andCs₂CO₃. This layer may react with the underlying electron transportlayer, the overlying cathode, or both. When an electron injection layeris present, the amount of material deposited is generally in the rangeof 1-100 Å, in some embodiments 1-10 Å.

The cathode 130 is an electrode that is particularly efficient forinjecting electrons or negative charge carriers. The cathode can be anymetal or nonmetal having a lower work function than the anode. Materialsfor the cathode can be selected from alkali metals of Group 1 (e.g., Li,Cs), the Group 2 (alkaline earth) metals, the Group 12 metals, includingthe rare earth elements and lanthanides, and the actinides. Materialssuch as aluminum, indium, calcium, barium, samarium and magnesium, aswell as combinations, can be used.

It is known to have other layers in organic electronic devices. Forexample, there can be layers (not shown) between the anode 110 and holeinjection layer (not shown) to control the amount of positive chargeinjected and/or to provide band-gap matching of the layers, or tofunction as a protective layer. Layers that are known in the art can beused, such as copper phthalocyanine, silicon oxy-nitride, fluorocarbons,silanes, or an ultra-thin layer of a metal, such as Pt. Alternatively,some or all of anode layer 110, active layer 120, or cathode layer 130,can be surface-treated to increase charge carrier transport efficiency.The choice of materials for each of the component layers is preferablydetermined by balancing the positive and negative charges in the emitterlayer to provide a device with high electroluminescence efficiency.

It is understood that each functional layer can be made up of more thanone layer.

The device layers can generally be formed by any deposition technique,or combinations of techniques, including vapor deposition, liquiddeposition, and thermal transfer. Substrates such as glass, plastics,and metals can be used. Conventional vapor deposition techniques can beused, such as thermal evaporation, chemical vapor deposition, and thelike. The organic layers can be applied from solutions or dispersions insuitable solvents, using conventional coating or printing techniques,including but not limited to coating, dip-coating, roll-to-rolltechniques, ink-jet printing, continuous nozzle printing,screen-printing, gravure printing and the like.

For liquid deposition methods, a suitable solvent for a particularcompound or related class of compounds can be readily determined by oneskilled in the art. For some applications, it is desirable that thecompounds be dissolved in non-aqueous solvents. Such non-aqueoussolvents can be relatively polar, such as C₁ to C₂₀ alcohols, ethers,and acid esters, or can be relatively non-polar such as C₁ to C₁₂alkanes or aromatics such as toluene, xylenes, trifluorotoluene and thelike. Other suitable liquids for use in making the liquid composition,either as a solution or dispersion as described herein, including thenew compounds, includes, but not limited to, chlorinated hydrocarbons(such as methylene chloride, chloroform, chlorobenzene), aromatichydrocarbons (such as substituted and non-substituted toluenes andxylenes), including trifluorotoluene), polar solvents (such astetrahydrofuran (THP), N-methyl pyrrolidone) esters (such asethylacetate) alcohols (isopropanol), ketones (cyclopentatone) andmixtures thereof. Suitable solvents for electroluminescent materialshave been described in, for example, published PCT application WO2007/145979.

In some embodiments, the device is fabricated by liquid deposition ofthe hole injection layer, the hole transport layer, and the photoactivelayer, and by vapor deposition of the anode, the electron transportlayer, an electron injection layer and the cathode onto the flexiblesubstrate.

It is understood that the efficiency of devices can be improved byoptimizing the other layers in the device. For example, more efficientcathodes such as Ca, Ba or LiF can be used. Shaped substrates and novelhole transport materials that result in a reduction in operating voltageor increase quantum efficiency are also applicable. Additional layerscan also be added to tailor the energy levels of the various layers andfacilitate electroluminescence.

In some embodiments, the device has the following structure, in order:substrate, anode, hole injection layer, hole transport layer,photoactive layer, electron transport layer, electron injection layer,cathode.

Although methods and materials similar or equivalent to those describedherein can be used in the practice or testing of the present invention,suitable methods and materials are described below. In addition, thematerials, methods, and examples are illustrative only and not intendedto be limiting. All publications, patent applications, patents, andother references mentioned herein are incorporated by reference in theirentirety.

EXAMPLES

The concepts described herein will be further illustrated in thefollowing examples, which do not limit the scope of the inventiondescribed in the claims.

Example 1

This example illustrates the preparation of a diamine having FormulaIII, and specifically Formula IIIA-1:4,4′-(naphthalene-2,6-diyl)bis(3-(trifluoromethyl)aniline), Compound 1.

In a 2 L, 3 neck round bottom flask equipped with a condenser andmagnetic stirrer2,6-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)naphthalene (33 g,0.087 mol), toluene (660 mL), 4-bromo-3-(trifluoromethyl)aniline (52.1g, 0.217 mol), 2M Na₂CO₃ solution (396 mL) and quaternary ammonium saltAliquat-336 (3.3 mL) were added sequentially at 25° C. under argon. Theresultant mixture was purged with argon gas for 10 min, Pd(PPh₃)₄ (10 g,0.009 mol) was added and again purged with argon gas for 10 min. Thereaction mixture was stirred at 85° C. After 16 h, the reaction mixturewas cooled to 30° C., filtered through a pad of Celite® diatomaceousearth, and the pad was washed with toluene (2×40 mL). The organic layerwas separated and the aq. layer was extracted with toluene (2×150 mL).The combined organic layer was concentrated under reduced pressure togive the crude product. The crude product was purified by silica gel(230-400 mesh) column chromatography using 15% EtOAc in petroleum etherfollowed by washing with 10% EtOH/CHCl₃ to afford 30 g of product with95.82% purity by UPLC. Further purification by recrystallization from 1,4-dioxane (twice) gave 16.1 g (42%) of the product as an off-white solidwith 99.98% purity by UPLC. MP: 198-201° C.

Example 2

This example illustrates the preparation of a liquid compositionincluding a polyamic acid having Formula I. The polyamic acid had thecomposition

BPDA/PMDA//Compound 1 97/3//100

Into a reaction flask equipped with a nitrogen inlet and outlet,mechanical stirrer, and thermocouple were Compound 1 and1-methyl-2-pyrrolidinone (NMP). The mixture was agitated under nitrogenat room temperature to dissolve compound 1. Afterwards,3,3′4,4′-biphenyl tetracarboxylic dianhydride (BPDA) was added slowly inportions to the stirring solution of the diamine followed bypyromellitic dianhydride (PMDA) in portions. After completion of thedianhydride addition, and additional additional NMP was used to wash inany remaining dianhydride powder from containers and the walls of thereaction flask. The dianhydrides dissolved and reacted and the polyamicacid (PAA) solution was stirred.

The final viscosity of the polymer solution was 11,080 cps at 25° C.,with 10% solids.

The contents of the flask were poured into a 2 liter HDPE bottle,tightly capped, and stored in a refrigerator for later use.

Example 3

This example illustrates the preparation of a polyimide film havingFormula IV.

A portion of the polyamic acid solution from Example 3 was pressurefiltered through a Whatman PolyCap HD 0.45 μm absolute filter into a EFDNordsen dispensing syringe barrel. This syringe barrel was attached toan EFD Nordsen dispensing unit to apply several ml of polymer solutiononto, and spin coat, a 6″ silicon wafer. The spin speed was varied intoorder to obtain the desired soft-baked thickness of about 18 μm.Soft-baking was accomplished after coating by placing the coated waferonto a hot plate set at about 110° C., first in proximity mode (nitrogenflow to hold wafer just off the surface of the hot plate), followed bydirect contact with the hot plate surface. The thickness of thesoft-baked film was measured on a Tencor profilometer by removingsections of the coating from the wafer and then measuring the differencebetween coated and uncoated areas of the wafer. The spin coatingconditions were varied as necessary to obtain the desired ˜15 μm uniformcoating across the wafer surface.

Afterwards, the spin coating conditions were determined, several waferswere coated, soft-baked and then these coated wafers were placed in aTempress tube furnace. After closing the furnace, a nitrogen purge wasapplied and the furnace was ramped to 100 C at 2.5° C./min and heldthere for about 30 min to allow a thorough purge with nitrogen, then thetemperature was ramped at 2° C./min to 200° C. and held there for 30min. Next, the temperature was ramped to 320° C. at 4° C./min and heldthere for 60 min. After this, the heating was stopped and thetemperature allowed to return slowly to ambient temperature (no externalcooling). Afterward, the wafers were removed from the furnace and thecoatings were removed from the wafers by scoring the coating around theedge of the wafer with a knife and then soaking the wafers in water forat least several hours to lift the coating off the wafer. The resultingpolyimide films allowed to dry and then subject to various propertymeasurements.

The polyimide film had a thickness of 11.4 μm, with the followingproperties:

Tensile modulus=10.9 GPa

Elongation to break=23.4%

CTE (first measurement)=3.4 ppm/° C.

CTE (second measurement)=1.4 ppm/° C.

1.0% TGA weight loss at 492.6° C.

Transmittance at 450 nm=61%

Transmittance at 550 nm=79%

Transmittance at 750 nm=85%

Example 4

This example illustrates the preparation of a diamine having FormulaIII, and specifically Formula IIIB-1:4,4′-(naphthalene-1,5-diyl)bis(3-(trifluoromethyl)aniline), Compound 17.

Step 1: Naphthalene-1,5-diyl bis(trifluoromethanesulfonate)

A 20 L 4-neck round bottom flask equipped with mechanical stirrer,internal thermometer and nitrogen bubbler was charged withnaphthalene-1,5-diol (500 g, 3124.0 mmol) and pyridine (1259 mL, 15620.0mmol) in dichloromethane (10000 mL) at room temperature.Trifluoromethanesulfonic anhydride (1320 mL, 7810.0 mmol) was addeddropwise at 5-10° C. over a period of 4 h. After completion oftrifluoromethanesulfonic anhydride addition, reaction mixture wasstirred at room temperature. After 16 h, the reaction mixture was pouredinto water (5000 mL) at 10-15° C. and stirred for 30 minutes. Theorganic layer was separated and the aqueous layer was extracted withdichloromethane (2×5000 mL). The combined organic phase was washed with1N HCl (7500 mL) and water (5000 mL), dried over anhydrous sodiumsulfate (Na₂SO₄), filtered, and concentrated under reduced pressure.Ethanol (2500 mL) was added to the crude solid and stirred for 30 min atroom temperature. The solid material was collected by filtration at roomtemperature and dried under vacuum to give naphthalene-1,5-diylbis(trifluoromethanesulfonate) (1190 g, 90%) as a grey solid. ¹H NMR(400 MHz, CDCl₃) δ: 8.15 (d, J=8.8 Hz, 2H), 7.69 (t, J=7.6 Hz, 2H), 7.61(dd, J=0.8 Hz and 7.6 Hz, 2H); UPLC: 99.24% purity.

Step 2: 1,5-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)naphthalene

A 20 L 4-neck round bottom flask equipped with mechanical stirrer,condenser, internal thermometer and nitrogen bubbler was charged withnaphthalene-1,5-diyl bis (trifluoromethanesulfonate) (547.0 g, 1290.2mmol), bis(pinacolato)diboron (721.0 g, 2838.5 mmol) and potassiumacetate (760 g, 7741.5 mmol) in 1,4-dioxane (5470 mL) at roomtemperature. The reaction mixture was purged with argon for 15 min, thenPdCl₂(dppf).DCM (53 g, 64.5 mmol) was added to the reaction mixture andargon was purged again for 10 min. The reaction mixture was heated to90-95° C. After 4 h, reaction mixture was cooled to room temperature,filtered through a bed of Celite®, and the bed was washed withdichloromethane (2500 mL). The combined filtrate was dried overanhydrous sodium sulfate, filtered, and concentrated under reducedpressure to give a black solid. Ethanol (2188 mL) was added to the solidand stirred for 30 min at room temperature. The solid material wascollected by filtration and dried under vacuum to give1,5-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)naphthalene (402 g,82%) as a grey solid. ¹H NMR (400 MHz, CDCl₃) δ: 8.89 (dd, J=1.2 Hz and8.0 Hz, 2H), 8.07 (dd, J=1.2 Hz and 6.8 Hz, 2H), 7.53 (dd, J=6.8 Hz and8.4 Hz, 2H), 1.42 (s, 24H); UPLC: 97.95% purity.

Step 3: 4,4′-(naphthalene-1,5-diyl)bis(3-(trifluoromethyl)aniline)

A 3 L 4-neck round bottom flask equipped with mechanical stirrer,internal thermometer and nitrogen bubbler was charged with1,5-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)naphthalene (40.0 g,105.2 mmol), 4-bromo-3-(trifluoromethyl)aniline (63.1 g, 263.4 mmol), 2Maq sodium carbonate solution (480 mL) and Aliquat-336 (4 mL) in toluene(800 mL). The reaction mixture was purged with argon for 15 min, thentetrakis(triphenylphosphine)palladium(0) (12.1 g, 10.5 mmol) was addedand the argon purge was continued for another 10 min. The reactionmixture was heated to 110-120° C. After 16 h, the reaction mixture wascooled to room temperature, diluted with toluene (650 mL), filteredthrough a bed of Celite®, and the bed was washed with toluene (100 mL).The organic layer was separated, washed with water (250 mL) and brine(100 mL), dried over anhydrous sodium sulfate, filtered and concentratedunder reduced pressure to get the crude residue. The residue waspurified by silica gel column chromatography (10-15% ethylacetate/hexanes as eluent) followed by co-precipitation usingethanol-chloroform (1:9) to afford a solid. The solid was dissolved in1,4-dioxane (200 mL), 4N HCl in 1,4-dioxane (100 mL) was added at 0-5°C. and stirring was continued for 1 h at room temperature. The resultingsolid was collected by filtration, washed with ethanol-ethyl acetate(3:7) and dried under vacuum to obtain the hydrochloride salt. A 5% KOHsolution (210 mL) was added to the salt in ethyl acetate (500 mL) at0-5° C. and stirring was continued for 1 h at room temperature. Theethyl acetate layer was separated, washed with water and brine, driedover anhydrous sodium sulfate, filtered, and concentrated under reducedpressure to give the4,4′-(naphthalene-1,5-diyl)bis(3-(trifluoromethyl)aniline) (15.87 g,34%) as an off-white solid. mp: 270-273° C.; FT-IR: 1258.50 cm⁻¹ (C—F);¹H NMR (400 MHz, CDCl₃) δ: 7.45 (d, J=7.6 Hz, 2H), 7.37-7.30 (m, 4H),7.20 (d, J=8.4 Hz, 2H), 7.12 (d, J=2.4 Hz, 2H), 6.92 (dd, J=2.4 Hz and8.0 Hz, 2H), 3.94 (s, 4H); ¹⁹F NMR (376 MHz, CDCl₃) δ: −58.78; GCMS:446.2 [M]⁺; UPLC: 99.95% purity as a mixture of two atropisomers.

Note that not all of the activities described above in the generaldescription or the examples are required, that a portion of a specificactivity may not be required, and that one or more further activitiesmay be performed in addition to those described. Still further, theorder in which activities are listed are not necessarily the order inwhich they are performed.

In the foregoing specification, the concepts have been described withreference to specific embodiments. However, one of ordinary skill in theart appreciates that various modifications and changes can be madewithout departing from the scope of the invention as set forth in theclaims below. Accordingly, the specification and figures are to beregarded in an illustrative rather than a restrictive sense, and allsuch modifications are intended to be included within the scope ofinvention.

Benefits, other advantages, and solutions to problems have beendescribed above with regard to specific embodiments. However, thebenefits, advantages, solutions to problems, and any feature(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeature of any or all the claims.

It is to be appreciated that certain features are, for clarity,described herein in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures that are, for brevity, described in the context of a singleembodiment, may also be provided separately or in any subcombination.The use of numerical values in the various ranges specified herein isstated as approximations as though the minimum and maximum values withinthe stated ranges were both being preceded by the word “about.” In thismanner, slight variations above and below the stated ranges can be usedto achieve substantially the same results as values within the ranges.Also, the disclosure of these ranges is intended as a continuous rangeincluding every value between the minimum and maximum average valuesincluding fractional values that can result when some of components ofone value are mixed with those of different value. Moreover, whenbroader and narrower ranges are disclosed, it is within thecontemplation of this invention to match a minimum value from one rangewith a maximum value from another range and vice versa.

What is claimed is:
 1. A liquid composition comprising (a) a polyamicacid having a repeat unit structure of Formula I

where: R^(a) is the same or different at each occurrence and representsone or more tetracarboxylic acid component residues; and R^(b) is thesame or different at each occurrence and represents one or more aromaticdiamine residues; wherein 30-100 mol % of R^(b) has Formula II

where: R¹ and R² are the same or different at each occurrence and areselected from the group consisting of halogen, alkyl, fluoroalkyl,silyl, alkoxy, fluoroalkoxy, and siloxy; a and b are the same ordifferent and are an integer from 0-4; c and d are the same or differentand are 1 or 2; and * indicates a point of attachment; and (b) ahigh-boiling aprotic solvent.
 2. The composition of claim 1, wherein30-100 mol % of R^(b) has a formula selected from the group consistingof Formula IIA, Formula IIB, Formula IIC, Formula IID, Formula IIE, andFormula IIF


3. The composition of claim 1, wherein 30-100 mol % of R^(b) has aformula selected from the group consisting of Formula IIA-1, FormulaIIB-1, Formula IIC-1, Formula IID-1, Formula IIE-1, and Formula IIF-1

where: R³ and R⁴ are the same or different and are selected from thegroup consisting of H, halogen, alkyl, fluoroalkyl, silyl, alkoxy,fluoroalkoxy, and siloxy.
 4. A polyimide having a repeat unit structureof Formula IV

where R^(a) is the same or different at each occurrence and representsone or more tetracarboxylic acid component residues; and R^(b) is thesame or different at each occurrence and represents one or more aromaticdiamine residues; wherein 30-100 mol % of R^(b) has Formula II

where: R¹ and R² are the same or different at each occurrence and areselected from the group consisting of halogen, alkyl, fluoroalkyl,silyl, alkoxy, fluoroalkoxy, and siloxy; a and b are the same ordifferent and are an integer from 0-4; c and d are the same or differentand are 1 or 2; and * indicates a point of attachment.
 5. The polyimideof claim 4, wherein 30-100 mol % of R^(b) has a formula selected fromthe group consisting of Formula IIA, Formula IIB, Formula IIC, FormulaIID, Formula IIE, and Formula IIF


6. The polyimide of claim 4, wherein 30-100 mol % of R^(b) has a formulaselected from the group consisting of Formula IIA-1, Formula IIB-1,Formula IIC-1, Formula IID-1, Formula IIE-1, and Formula IIF-1

where: R³ and R⁴ are the same or different and are selected from thegroup consisting of H, halogen, alkyl, fluoroalkyl, silyl, alkoxy,fluoroalkoxy, and siloxy.
 7. A polyimide film comprising a repeat unitof Formula IV, according to claim
 4. 8. An organic electronic devicehaving at least one layer comprising a polyimide film having a repeatunit of Formula IV, according to claim
 4. 9. The electronic deviceaccording to claim 8, wherein the layer is used in device componentsselected from the group consisting of device substrates, substrates forcolor filter sheets, cover films, and touch screen panels.